add support for 24-bit input
[flac.git] / src / libFLAC / encoder.c
1 /* libFLAC - Free Lossless Audio Codec library
2  * Copyright (C) 2000,2001  Josh Coalson
3  *
4  * This library is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Library General Public
6  * License as published by the Free Software Foundation; either
7  * version 2 of the License, or (at your option) any later version.
8  *
9  * This library is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Library General Public License for more details.
13  *
14  * You should have received a copy of the GNU Library General Public
15  * License along with this library; if not, write to the
16  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
17  * Boston, MA  02111-1307, USA.
18  */
19
20 #include <assert.h>
21 #include <stdio.h>
22 #include <stdlib.h> /* for malloc() */
23 #include <string.h> /* for memcpy() */
24 #include "FLAC/encoder.h"
25 #include "private/bitbuffer.h"
26 #include "private/encoder_framing.h"
27 #include "private/fixed.h"
28 #include "private/lpc.h"
29 #include "private/md5.h"
30
31 #ifdef min
32 #undef min
33 #endif
34 #define min(x,y) ((x)<(y)?(x):(y))
35
36 #ifdef max
37 #undef max
38 #endif
39 #define max(x,y) ((x)>(y)?(x):(y))
40
41 typedef struct FLAC__EncoderPrivate {
42         unsigned input_capacity;                    /* current size (in samples) of the signal and residual buffers */
43         int32 *integer_signal[FLAC__MAX_CHANNELS];  /* the integer version of the input signal */
44         int32 *integer_signal_mid_side[2];          /* the integer version of the mid-side input signal (stereo only) */
45         real *real_signal[FLAC__MAX_CHANNELS];      /* the floating-point version of the input signal */
46         real *real_signal_mid_side[2];              /* the floating-point version of the mid-side input signal (stereo only) */
47         int32 *residual_workspace[FLAC__MAX_CHANNELS][2]; /* each channel has a candidate and best workspace where the subframe residual signals will be stored */
48         int32 *residual_workspace_mid_side[2][2];
49         FLAC__Subframe subframe_workspace[FLAC__MAX_CHANNELS][2];
50         FLAC__Subframe subframe_workspace_mid_side[2][2];
51         FLAC__Subframe *subframe_workspace_ptr[FLAC__MAX_CHANNELS][2];
52         FLAC__Subframe *subframe_workspace_ptr_mid_side[2][2];
53         unsigned best_subframe[FLAC__MAX_CHANNELS]; /* index into the above workspaces */
54         unsigned best_subframe_mid_side[2];
55         unsigned best_subframe_bits[FLAC__MAX_CHANNELS]; /* size in bits of the best subframe for each channel */
56         unsigned best_subframe_bits_mid_side[2];
57         uint32 *abs_residual;                       /* workspace where the abs(candidate residual) is stored */
58         FLAC__BitBuffer frame;                      /* the current frame being worked on */
59         bool current_frame_can_do_mid_side;         /* encoder sets this false when any given sample of a frame's side channel exceeds 16 bits */
60         double loose_mid_side_stereo_frames_exact;  /* exact number of frames the encoder will use before trying both independent and mid/side frames again */
61         unsigned loose_mid_side_stereo_frames;      /* rounded number of frames the encoder will use before trying both independent and mid/side frames again */
62         unsigned loose_mid_side_stereo_frame_count; /* number of frames using the current channel assignment */
63         FLAC__ChannelAssignment last_channel_assignment;
64         FLAC__StreamMetaData metadata;
65         unsigned current_sample_number;
66         unsigned current_frame_number;
67         struct MD5Context md5context;
68         FLAC__EncoderWriteStatus (*write_callback)(const FLAC__Encoder *encoder, const byte buffer[], unsigned bytes, unsigned samples, unsigned current_frame, void *client_data);
69         void (*metadata_callback)(const FLAC__Encoder *encoder, const FLAC__StreamMetaData *metadata, void *client_data);
70         void *client_data;
71 } FLAC__EncoderPrivate;
72
73 static bool encoder_resize_buffers_(FLAC__Encoder *encoder, unsigned new_size);
74 static bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame);
75 static bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame);
76 static bool encoder_process_subframe_(FLAC__Encoder *encoder, unsigned max_partition_order, bool verbatim_only, const FLAC__FrameHeader *frame_header, unsigned bits_per_sample, const int32 integer_signal[], const real real_signal[], FLAC__Subframe *subframe[2], int32 *residual[2], unsigned *best_subframe, unsigned *best_bits);
77 static bool encoder_add_subframe_(FLAC__Encoder *encoder, const FLAC__FrameHeader *frame_header, unsigned bits_per_sample, const FLAC__Subframe *subframe, FLAC__BitBuffer *frame);
78 static unsigned encoder_evaluate_constant_subframe_(const int32 signal, unsigned bits_per_sample, FLAC__Subframe *subframe);
79 static unsigned encoder_evaluate_fixed_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe);
80 static unsigned encoder_evaluate_lpc_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], const real lp_coeff[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned qlp_coeff_precision, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe);
81 static unsigned encoder_evaluate_verbatim_subframe_(const int32 signal[], unsigned blocksize, unsigned bits_per_sample, FLAC__Subframe *subframe);
82 static unsigned encoder_find_best_partition_order_(const int32 residual[], uint32 abs_residual[], unsigned residual_samples, unsigned predictor_order, unsigned rice_parameter, unsigned max_partition_order, unsigned *best_partition_order, unsigned best_parameters[]);
83 static bool encoder_set_partitioned_rice_(const uint32 abs_residual[], const unsigned residual_samples, const unsigned predictor_order, const unsigned rice_parameter, const unsigned partition_order, unsigned parameters[], unsigned *bits);
84
85 const char *FLAC__EncoderWriteStatusString[] = {
86         "FLAC__ENCODER_WRITE_OK",
87         "FLAC__ENCODER_WRITE_FATAL_ERROR"
88 };
89
90 const char *FLAC__EncoderStateString[] = {
91         "FLAC__ENCODER_OK",
92         "FLAC__ENCODER_UNINITIALIZED",
93         "FLAC__ENCODER_INVALID_NUMBER_OF_CHANNELS",
94         "FLAC__ENCODER_INVALID_BITS_PER_SAMPLE",
95         "FLAC__ENCODER_INVALID_SAMPLE_RATE",
96         "FLAC__ENCODER_INVALID_BLOCK_SIZE",
97         "FLAC__ENCODER_INVALID_QLP_COEFF_PRECISION",
98         "FLAC__ENCODER_MID_SIDE_CHANNELS_MISMATCH",
99         "FLAC__ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH",
100         "FLAC__ENCODER_ILLEGAL_MID_SIDE_FORCE",
101         "FLAC__ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER",
102         "FLAC__ENCODER_NOT_STREAMABLE",
103         "FLAC__ENCODER_FRAMING_ERROR",
104         "FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING",
105         "FLAC__ENCODER_FATAL_ERROR_WHILE_WRITING",
106         "FLAC__ENCODER_MEMORY_ALLOCATION_ERROR"
107 };
108
109
110 bool encoder_resize_buffers_(FLAC__Encoder *encoder, unsigned new_size)
111 {
112         bool ok;
113         unsigned i, channel;
114         int32 *previous_is, *current_is;
115         real *previous_rs, *current_rs;
116         int32 *residual;
117         uint32 *abs_residual;
118
119         assert(new_size > 0);
120         assert(encoder->state == FLAC__ENCODER_OK);
121         assert(encoder->guts->current_sample_number == 0);
122
123         /* To avoid excessive malloc'ing, we only grow the buffer; no shrinking. */
124         if(new_size <= encoder->guts->input_capacity)
125                 return true;
126
127         ok = 1;
128         if(ok) {
129                 for(i = 0; ok && i < encoder->channels; i++) {
130                         /* integer version of the signal */
131                         previous_is = encoder->guts->integer_signal[i];
132                         current_is = (int32*)malloc(sizeof(int32) * new_size);
133                         if(0 == current_is) {
134                                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
135                                 ok = 0;
136                         }
137                         else {
138                                 encoder->guts->integer_signal[i] = current_is;
139                                 if(previous_is != 0)
140                                         free(previous_is);
141                         }
142                         /* real version of the signal */
143                         previous_rs = encoder->guts->real_signal[i];
144                         current_rs = (real*)malloc(sizeof(real) * new_size);
145                         if(0 == current_rs) {
146                                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
147                                 ok = 0;
148                         }
149                         else {
150                                 encoder->guts->real_signal[i] = current_rs;
151                                 if(previous_rs != 0)
152                                         free(previous_rs);
153                         }
154                 }
155         }
156         if(ok) {
157                 for(i = 0; ok && i < 2; i++) {
158                         /* integer version of the signal */
159                         previous_is = encoder->guts->integer_signal_mid_side[i];
160                         current_is = (int32*)malloc(sizeof(int32) * new_size);
161                         if(0 == current_is) {
162                                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
163                                 ok = 0;
164                         }
165                         else {
166                                 encoder->guts->integer_signal_mid_side[i] = current_is;
167                                 if(previous_is != 0)
168                                         free(previous_is);
169                         }
170                         /* real version of the signal */
171                         previous_rs = encoder->guts->real_signal_mid_side[i];
172                         current_rs = (real*)malloc(sizeof(real) * new_size);
173                         if(0 == current_rs) {
174                                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
175                                 ok = 0;
176                         }
177                         else {
178                                 encoder->guts->real_signal_mid_side[i] = current_rs;
179                                 if(previous_rs != 0)
180                                         free(previous_rs);
181                         }
182                 }
183         }
184         if(ok) {
185                 for(channel = 0; channel < encoder->channels; channel++) {
186                         for(i = 0; i < 2; i++) {
187                                 residual = (int32*)malloc(sizeof(int32) * new_size);
188                                 if(0 == residual) {
189                                         encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
190                                         ok = 0;
191                                 }
192                                 else {
193                                         if(encoder->guts->residual_workspace[channel][i] != 0)
194                                                 free(encoder->guts->residual_workspace[channel][i]);
195                                         encoder->guts->residual_workspace[channel][i] = residual;
196                                 }
197                         }
198                 }
199                 for(channel = 0; channel < 2; channel++) {
200                         for(i = 0; i < 2; i++) {
201                                 residual = (int32*)malloc(sizeof(int32) * new_size);
202                                 if(0 == residual) {
203                                         encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
204                                         ok = 0;
205                                 }
206                                 else {
207                                         if(encoder->guts->residual_workspace_mid_side[channel][i] != 0)
208                                                 free(encoder->guts->residual_workspace_mid_side[channel][i]);
209                                         encoder->guts->residual_workspace_mid_side[channel][i] = residual;
210                                 }
211                         }
212                 }
213                 abs_residual = (uint32*)malloc(sizeof(uint32) * new_size);
214                 if(0 == residual) {
215                         encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
216                         ok = 0;
217                 }
218                 else {
219                         if(encoder->guts->abs_residual != 0)
220                                 free(encoder->guts->abs_residual);
221                         encoder->guts->abs_residual = abs_residual;
222                 }
223         }
224         if(ok)
225                 encoder->guts->input_capacity = new_size;
226
227         return ok;
228 }
229
230 FLAC__Encoder *FLAC__encoder_get_new_instance()
231 {
232         FLAC__Encoder *encoder = (FLAC__Encoder*)malloc(sizeof(FLAC__Encoder));
233         if(encoder != 0) {
234                 encoder->state = FLAC__ENCODER_UNINITIALIZED;
235                 encoder->guts = 0;
236         }
237         return encoder;
238 }
239
240 void FLAC__encoder_free_instance(FLAC__Encoder *encoder)
241 {
242         assert(encoder != 0);
243         free(encoder);
244 }
245
246 FLAC__EncoderState FLAC__encoder_init(FLAC__Encoder *encoder, FLAC__EncoderWriteStatus (*write_callback)(const FLAC__Encoder *encoder, const byte buffer[], unsigned bytes, unsigned samples, unsigned current_frame, void *client_data), void (*metadata_callback)(const FLAC__Encoder *encoder, const FLAC__StreamMetaData *metadata, void *client_data), void *client_data)
247 {
248         unsigned i;
249         FLAC__StreamMetaData padding;
250
251         assert(sizeof(int) >= 4); /* we want to die right away if this is not true */
252         assert(encoder != 0);
253         assert(write_callback != 0);
254         assert(metadata_callback != 0);
255         assert(encoder->state == FLAC__ENCODER_UNINITIALIZED);
256         assert(encoder->guts == 0);
257
258         encoder->state = FLAC__ENCODER_OK;
259
260         if(encoder->channels == 0 || encoder->channels > FLAC__MAX_CHANNELS)
261                 return encoder->state = FLAC__ENCODER_INVALID_NUMBER_OF_CHANNELS;
262
263         if(encoder->do_mid_side_stereo && encoder->channels != 2)
264                 return encoder->state = FLAC__ENCODER_MID_SIDE_CHANNELS_MISMATCH;
265
266 /*@@@ necessary?
267         if(encoder->do_mid_side_stereo && encoder->bits_per_sample > 16)
268                 return encoder->state = FLAC__ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH;
269 */
270
271         if(encoder->loose_mid_side_stereo && !encoder->do_mid_side_stereo)
272                 return encoder->state = FLAC__ENCODER_ILLEGAL_MID_SIDE_FORCE;
273
274         if(encoder->bits_per_sample == 0 || encoder->bits_per_sample > FLAC__MAX_BITS_PER_SAMPLE)
275                 return encoder->state = FLAC__ENCODER_INVALID_BITS_PER_SAMPLE;
276
277         if(encoder->sample_rate == 0 || encoder->sample_rate > FLAC__MAX_SAMPLE_RATE)
278                 return encoder->state = FLAC__ENCODER_INVALID_SAMPLE_RATE;
279
280         if(encoder->blocksize < FLAC__MIN_BLOCK_SIZE || encoder->blocksize > FLAC__MAX_BLOCK_SIZE)
281                 return encoder->state = FLAC__ENCODER_INVALID_BLOCK_SIZE;
282
283         if(encoder->blocksize < encoder->max_lpc_order)
284                 return encoder->state = FLAC__ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER;
285
286         if(encoder->qlp_coeff_precision == 0) {
287                 if(encoder->bits_per_sample < 16) {
288                         /* @@@ need some data about how to set this here w.r.t. blocksize and sample rate */
289                         /* @@@ until then we'll make a guess */
290                         encoder->qlp_coeff_precision = max(5, 2 + encoder->bits_per_sample / 2);
291                 }
292                 else if(encoder->bits_per_sample == 16) {
293                         if(encoder->blocksize <= 192)
294                                 encoder->qlp_coeff_precision = 7;
295                         else if(encoder->blocksize <= 384)
296                                 encoder->qlp_coeff_precision = 8;
297                         else if(encoder->blocksize <= 576)
298                                 encoder->qlp_coeff_precision = 9;
299                         else if(encoder->blocksize <= 1152)
300                                 encoder->qlp_coeff_precision = 10;
301                         else if(encoder->blocksize <= 2304)
302                                 encoder->qlp_coeff_precision = 11;
303                         else if(encoder->blocksize <= 4608)
304                                 encoder->qlp_coeff_precision = 12;
305                         else
306                                 encoder->qlp_coeff_precision = 13;
307                 }
308                 else {
309                         encoder->qlp_coeff_precision = min(13, 8*sizeof(int32) - encoder->bits_per_sample - 1);
310                 }
311         }
312         else if(encoder->qlp_coeff_precision < FLAC__MIN_QLP_COEFF_PRECISION || encoder->qlp_coeff_precision + encoder->bits_per_sample >= 8*sizeof(uint32) || encoder->qlp_coeff_precision >= (1u<<FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN))
313                 return encoder->state = FLAC__ENCODER_INVALID_QLP_COEFF_PRECISION;
314
315         if(encoder->streamable_subset) {
316                 if(encoder->bits_per_sample != 8 && encoder->bits_per_sample != 12 && encoder->bits_per_sample != 16 && encoder->bits_per_sample != 20 && encoder->bits_per_sample != 24)
317                         return encoder->state = FLAC__ENCODER_NOT_STREAMABLE;
318                 if(encoder->sample_rate > 655350)
319                         return encoder->state = FLAC__ENCODER_NOT_STREAMABLE;
320         }
321
322         if(encoder->rice_optimization_level >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN))
323                 encoder->rice_optimization_level = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN) - 1;
324
325         encoder->guts = (FLAC__EncoderPrivate*)malloc(sizeof(FLAC__EncoderPrivate));
326         if(encoder->guts == 0)
327                 return encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
328
329         encoder->guts->input_capacity = 0;
330         for(i = 0; i < encoder->channels; i++) {
331                 encoder->guts->integer_signal[i] = 0;
332                 encoder->guts->real_signal[i] = 0;
333         }
334         for(i = 0; i < 2; i++) {
335                 encoder->guts->integer_signal_mid_side[i] = 0;
336                 encoder->guts->real_signal_mid_side[i] = 0;
337         }
338         for(i = 0; i < encoder->channels; i++) {
339                 encoder->guts->residual_workspace[i][0] = encoder->guts->residual_workspace[i][1] = 0;
340                 encoder->guts->best_subframe[i] = 0;
341         }
342         for(i = 0; i < 2; i++) {
343                 encoder->guts->residual_workspace_mid_side[i][0] = encoder->guts->residual_workspace_mid_side[i][1] = 0;
344                 encoder->guts->best_subframe_mid_side[i] = 0;
345         }
346         for(i = 0; i < encoder->channels; i++) {
347                 encoder->guts->subframe_workspace_ptr[i][0] = &encoder->guts->subframe_workspace[i][0];
348                 encoder->guts->subframe_workspace_ptr[i][1] = &encoder->guts->subframe_workspace[i][1];
349         }
350         for(i = 0; i < 2; i++) {
351                 encoder->guts->subframe_workspace_ptr_mid_side[i][0] = &encoder->guts->subframe_workspace_mid_side[i][0];
352                 encoder->guts->subframe_workspace_ptr_mid_side[i][1] = &encoder->guts->subframe_workspace_mid_side[i][1];
353         }
354         encoder->guts->abs_residual = 0;
355         encoder->guts->current_frame_can_do_mid_side = true;
356         encoder->guts->loose_mid_side_stereo_frames_exact = (double)encoder->sample_rate * 0.4 / (double)encoder->blocksize;
357         encoder->guts->loose_mid_side_stereo_frames = (unsigned)(encoder->guts->loose_mid_side_stereo_frames_exact + 0.5);
358         if(encoder->guts->loose_mid_side_stereo_frames == 0)
359                 encoder->guts->loose_mid_side_stereo_frames = 1;
360         encoder->guts->loose_mid_side_stereo_frame_count = 0;
361         encoder->guts->current_sample_number = 0;
362         encoder->guts->current_frame_number = 0;
363
364         if(!encoder_resize_buffers_(encoder, encoder->blocksize)) {
365                 /* the above function sets the state for us in case of an error */
366                 return encoder->state;
367         }
368         FLAC__bitbuffer_init(&encoder->guts->frame);
369         encoder->guts->write_callback = write_callback;
370         encoder->guts->metadata_callback = metadata_callback;
371         encoder->guts->client_data = client_data;
372
373         /*
374          * write the stream header
375          */
376         if(!FLAC__bitbuffer_clear(&encoder->guts->frame))
377                 return encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
378
379         if(!FLAC__bitbuffer_write_raw_uint32(&encoder->guts->frame, FLAC__STREAM_SYNC, FLAC__STREAM_SYNC_LEN))
380                 return encoder->state = FLAC__ENCODER_FRAMING_ERROR;
381
382         encoder->guts->metadata.type = FLAC__METADATA_TYPE_STREAMINFO;
383         encoder->guts->metadata.is_last = (encoder->padding == 0);
384         encoder->guts->metadata.length = FLAC__STREAM_METADATA_STREAMINFO_LENGTH;
385         encoder->guts->metadata.data.stream_info.min_blocksize = encoder->blocksize; /* this encoder uses the same blocksize for the whole stream */
386         encoder->guts->metadata.data.stream_info.max_blocksize = encoder->blocksize;
387         encoder->guts->metadata.data.stream_info.min_framesize = 0; /* we don't know this yet; have to fill it in later */
388         encoder->guts->metadata.data.stream_info.max_framesize = 0; /* we don't know this yet; have to fill it in later */
389         encoder->guts->metadata.data.stream_info.sample_rate = encoder->sample_rate;
390         encoder->guts->metadata.data.stream_info.channels = encoder->channels;
391         encoder->guts->metadata.data.stream_info.bits_per_sample = encoder->bits_per_sample;
392         encoder->guts->metadata.data.stream_info.total_samples = encoder->total_samples_estimate; /* we will replace this later with the real total */
393         memset(encoder->guts->metadata.data.stream_info.md5sum, 0, 16); /* we don't know this yet; have to fill it in later */
394         MD5Init(&encoder->guts->md5context);
395         if(!FLAC__add_metadata_block(&encoder->guts->metadata, &encoder->guts->frame))
396                 return encoder->state = FLAC__ENCODER_FRAMING_ERROR;
397
398         /* add a PADDING block if requested */
399         if(encoder->padding > 0) {
400                 padding.type = FLAC__METADATA_TYPE_PADDING;
401                 padding.is_last = true;
402                 padding.length = encoder->padding;
403                 if(!FLAC__add_metadata_block(&padding, &encoder->guts->frame))
404                         return encoder->state = FLAC__ENCODER_FRAMING_ERROR;
405         }
406
407         assert(encoder->guts->frame.bits == 0); /* assert that we're byte-aligned before writing */
408         assert(encoder->guts->frame.total_consumed_bits == 0); /* assert that no reading of the buffer was done */
409         if(encoder->guts->write_callback(encoder, encoder->guts->frame.buffer, encoder->guts->frame.bytes, 0, encoder->guts->current_frame_number, encoder->guts->client_data) != FLAC__ENCODER_WRITE_OK)
410                 return encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_WRITING;
411
412         /* now that the metadata block is written, we can init this to an absurdly-high value... */
413         encoder->guts->metadata.data.stream_info.min_framesize = (1u << FLAC__STREAM_METADATA_STREAMINFO_MIN_FRAME_SIZE_LEN) - 1;
414         /* ... and clear this to 0 */
415         encoder->guts->metadata.data.stream_info.total_samples = 0;
416
417         return encoder->state;
418 }
419
420 void FLAC__encoder_finish(FLAC__Encoder *encoder)
421 {
422         unsigned i, channel;
423
424         assert(encoder != 0);
425         if(encoder->state == FLAC__ENCODER_UNINITIALIZED)
426                 return;
427         if(encoder->guts->current_sample_number != 0) {
428                 encoder->blocksize = encoder->guts->current_sample_number;
429                 encoder_process_frame_(encoder, true); /* true => is last frame */
430         }
431         MD5Final(encoder->guts->metadata.data.stream_info.md5sum, &encoder->guts->md5context);
432         encoder->guts->metadata_callback(encoder, &encoder->guts->metadata, encoder->guts->client_data);
433         if(encoder->guts != 0) {
434                 for(i = 0; i < encoder->channels; i++) {
435                         if(encoder->guts->integer_signal[i] != 0) {
436                                 free(encoder->guts->integer_signal[i]);
437                                 encoder->guts->integer_signal[i] = 0;
438                         }
439                         if(encoder->guts->real_signal[i] != 0) {
440                                 free(encoder->guts->real_signal[i]);
441                                 encoder->guts->real_signal[i] = 0;
442                         }
443                 }
444                 for(i = 0; i < 2; i++) {
445                         if(encoder->guts->integer_signal_mid_side[i] != 0) {
446                                 free(encoder->guts->integer_signal_mid_side[i]);
447                                 encoder->guts->integer_signal_mid_side[i] = 0;
448                         }
449                         if(encoder->guts->real_signal_mid_side[i] != 0) {
450                                 free(encoder->guts->real_signal_mid_side[i]);
451                                 encoder->guts->real_signal_mid_side[i] = 0;
452                         }
453                 }
454                 for(channel = 0; channel < encoder->channels; channel++) {
455                         for(i = 0; i < 2; i++) {
456                                 if(encoder->guts->residual_workspace[channel][i] != 0) {
457                                         free(encoder->guts->residual_workspace[channel][i]);
458                                         encoder->guts->residual_workspace[channel][i] = 0;
459                                 }
460                         }
461                 }
462                 for(channel = 0; channel < 2; channel++) {
463                         for(i = 0; i < 2; i++) {
464                                 if(encoder->guts->residual_workspace_mid_side[channel][i] != 0) {
465                                         free(encoder->guts->residual_workspace_mid_side[channel][i]);
466                                         encoder->guts->residual_workspace_mid_side[channel][i] = 0;
467                                 }
468                         }
469                 }
470                 if(encoder->guts->abs_residual != 0) {
471                         free(encoder->guts->abs_residual);
472                         encoder->guts->abs_residual = 0;
473                 }
474                 FLAC__bitbuffer_free(&encoder->guts->frame);
475                 free(encoder->guts);
476                 encoder->guts = 0;
477         }
478         encoder->state = FLAC__ENCODER_UNINITIALIZED;
479 }
480
481 bool FLAC__encoder_process(FLAC__Encoder *encoder, const int32 *buf[], unsigned samples)
482 {
483         unsigned i, j, channel;
484         int32 x, mid, side;
485         const bool ms = encoder->do_mid_side_stereo && encoder->channels == 2;
486         const int32 min_side = -((int64)1 << (encoder->bits_per_sample-1));
487         const int32 max_side =  ((int64)1 << (encoder->bits_per_sample-1)) - 1;
488
489         assert(encoder != 0);
490         assert(encoder->state == FLAC__ENCODER_OK);
491
492         j = 0;
493         do {
494                 for(i = encoder->guts->current_sample_number; i < encoder->blocksize && j < samples; i++, j++) {
495                         for(channel = 0; channel < encoder->channels; channel++) {
496                                 x = buf[channel][j];
497                                 encoder->guts->integer_signal[channel][i] = x;
498                                 encoder->guts->real_signal[channel][i] = (real)x;
499                         }
500                         if(ms && encoder->guts->current_frame_can_do_mid_side) {
501                                 side = buf[0][j] - buf[1][j];
502                                 if(side < min_side || side > max_side) {
503                                         encoder->guts->current_frame_can_do_mid_side = false;
504                                 }
505                                 else {
506                                         mid = (buf[0][j] + buf[1][j]) >> 1; /* NOTE: not the same as 'mid = (buf[0][j] + buf[1][j]) / 2' ! */
507                                         encoder->guts->integer_signal_mid_side[0][i] = mid;
508                                         encoder->guts->integer_signal_mid_side[1][i] = side;
509                                         encoder->guts->real_signal_mid_side[0][i] = (real)mid;
510                                         encoder->guts->real_signal_mid_side[1][i] = (real)side;
511                                 }
512                         }
513                         encoder->guts->current_sample_number++;
514                 }
515                 if(i == encoder->blocksize) {
516                         if(!encoder_process_frame_(encoder, false)) /* false => not last frame */
517                                 return false;
518                 }
519         } while(j < samples);
520
521         return true;
522 }
523
524 /* 'samples' is channel-wide samples, e.g. for 1 second at 44100Hz, 'samples' = 44100 regardless of the number of channels */
525 bool FLAC__encoder_process_interleaved(FLAC__Encoder *encoder, const int32 buf[], unsigned samples)
526 {
527         unsigned i, j, k, channel;
528         int32 x, left = 0, mid, side;
529         const bool ms = encoder->do_mid_side_stereo && encoder->channels == 2;
530         const int32 min_side = -((int64)1 << (encoder->bits_per_sample-1));
531         const int32 max_side =  ((int64)1 << (encoder->bits_per_sample-1)) - 1;
532
533         assert(encoder != 0);
534         assert(encoder->state == FLAC__ENCODER_OK);
535
536         j = k = 0;
537         do {
538                 for(i = encoder->guts->current_sample_number; i < encoder->blocksize && j < samples; i++, j++, k++) {
539                         for(channel = 0; channel < encoder->channels; channel++, k++) {
540                                 x = buf[k];
541                                 encoder->guts->integer_signal[channel][i] = x;
542                                 encoder->guts->real_signal[channel][i] = (real)x;
543                                 if(ms && encoder->guts->current_frame_can_do_mid_side) {
544                                         if(channel == 0) {
545                                                 left = x;
546                                         }
547                                         else {
548                                                 side = left - x;
549                                                 if(side < min_side || side > max_side) {
550                                                         encoder->guts->current_frame_can_do_mid_side = false;
551                                                 }
552                                                 else {
553                                                         mid = (left + x) >> 1; /* NOTE: not the same as 'mid = (left + x) / 2' ! */
554                                                         encoder->guts->integer_signal_mid_side[0][i] = mid;
555                                                         encoder->guts->integer_signal_mid_side[1][i] = side;
556                                                         encoder->guts->real_signal_mid_side[0][i] = (real)mid;
557                                                         encoder->guts->real_signal_mid_side[1][i] = (real)side;
558                                                 }
559                                         }
560                                 }
561                         }
562                         encoder->guts->current_sample_number++;
563                 }
564                 if(i == encoder->blocksize) {
565                         if(!encoder_process_frame_(encoder, false)) /* false => not last frame */
566                                 return false;
567                 }
568         } while(j < samples);
569
570         return true;
571 }
572
573 bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame)
574 {
575         assert(encoder->state == FLAC__ENCODER_OK);
576
577         /*
578          * Accumulate raw signal to the MD5 signature
579          */
580         if(!FLAC__MD5Accumulate(&encoder->guts->md5context, encoder->guts->integer_signal, encoder->channels, encoder->blocksize, (encoder->bits_per_sample+7) / 8)) {
581                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
582                 return false;
583         }
584
585         /*
586          * Process the frame header and subframes into the frame bitbuffer
587          */
588         if(!encoder_process_subframes_(encoder, is_last_frame)) {
589                 /* the above function sets the state for us in case of an error */
590                 return false;
591         }
592
593         /*
594          * Zero-pad the frame to a byte_boundary
595          */
596         if(!FLAC__bitbuffer_zero_pad_to_byte_boundary(&encoder->guts->frame)) {
597                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
598                 return false;
599         }
600
601         /*
602          * Write it
603          */
604         assert(encoder->guts->frame.bits == 0); /* assert that we're byte-aligned before writing */
605         assert(encoder->guts->frame.total_consumed_bits == 0); /* assert that no reading of the buffer was done */
606         if(encoder->guts->write_callback(encoder, encoder->guts->frame.buffer, encoder->guts->frame.bytes, encoder->blocksize, encoder->guts->current_frame_number, encoder->guts->client_data) != FLAC__ENCODER_WRITE_OK) {
607                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_WRITING;
608                 return false;
609         }
610
611         /*
612          * Get ready for the next frame
613          */
614         encoder->guts->current_frame_can_do_mid_side = true;
615         encoder->guts->current_sample_number = 0;
616         encoder->guts->current_frame_number++;
617         encoder->guts->metadata.data.stream_info.total_samples += (uint64)encoder->blocksize;
618         encoder->guts->metadata.data.stream_info.min_framesize = min(encoder->guts->frame.bytes, encoder->guts->metadata.data.stream_info.min_framesize);
619         encoder->guts->metadata.data.stream_info.max_framesize = max(encoder->guts->frame.bytes, encoder->guts->metadata.data.stream_info.max_framesize);
620
621         return true;
622 }
623
624 bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame)
625 {
626         FLAC__FrameHeader frame_header;
627         unsigned channel, max_partition_order;
628         bool do_independent, do_mid_side;
629
630         /*
631          * Calculate the max Rice partition order
632          */
633         if(is_last_frame) {
634                 max_partition_order = 0;
635         }
636         else {
637                 unsigned limit = 0, b = encoder->blocksize;
638                 while(!(b & 1)) {
639                         limit++;
640                         b >>= 1;
641                 }
642                 max_partition_order = min(encoder->rice_optimization_level, limit);
643         }
644
645         /*
646          * Setup the frame
647          */
648         if(!FLAC__bitbuffer_clear(&encoder->guts->frame)) {
649                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
650                 return false;
651         }
652         frame_header.blocksize = encoder->blocksize;
653         frame_header.sample_rate = encoder->sample_rate;
654         frame_header.channels = encoder->channels;
655         frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT; /* the default unless the encoder determines otherwise */
656         frame_header.bits_per_sample = encoder->bits_per_sample;
657         frame_header.number.frame_number = encoder->guts->current_frame_number;
658
659         /*
660          * Figure out what channel assignments to try
661          */
662         if(encoder->do_mid_side_stereo) {
663                 if(encoder->loose_mid_side_stereo) {
664                         if(encoder->guts->loose_mid_side_stereo_frame_count == 0) {
665                                 do_independent = true;
666                                 do_mid_side = true;
667                         }
668                         else {
669                                 do_independent = (encoder->guts->last_channel_assignment == FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT);
670                                 do_mid_side = !do_independent;
671                         }
672                 }
673                 else {
674                         do_independent = true;
675                         do_mid_side = true;
676                 }
677         }
678         else {
679                 do_independent = true;
680                 do_mid_side = false;
681         }
682         if(do_mid_side && !encoder->guts->current_frame_can_do_mid_side) {
683                 do_independent = true;
684                 do_mid_side = false;
685         }
686
687         assert(do_independent || do_mid_side);
688
689         /*
690          * First do a normal encoding pass of each independent channel
691          */
692         if(do_independent) {
693                 for(channel = 0; channel < encoder->channels; channel++) {
694                         if(!encoder_process_subframe_(encoder, max_partition_order, false, &frame_header, encoder->bits_per_sample, encoder->guts->integer_signal[channel], encoder->guts->real_signal[channel], encoder->guts->subframe_workspace_ptr[channel], encoder->guts->residual_workspace[channel], encoder->guts->best_subframe+channel, encoder->guts->best_subframe_bits+channel))
695                                 return false;
696                 }
697         }
698
699         /*
700          * Now do mid and side channels if requested
701          */
702         if(do_mid_side) {
703                 assert(encoder->channels == 2);
704
705                 for(channel = 0; channel < 2; channel++) {
706                         if(!encoder_process_subframe_(encoder, max_partition_order, false, &frame_header, encoder->bits_per_sample+(channel==0? 0:1), encoder->guts->integer_signal_mid_side[channel], encoder->guts->real_signal_mid_side[channel], encoder->guts->subframe_workspace_ptr_mid_side[channel], encoder->guts->residual_workspace_mid_side[channel], encoder->guts->best_subframe_mid_side+channel, encoder->guts->best_subframe_bits_mid_side+channel))
707                                 return false;
708                 }
709         }
710
711         /*
712          * Compose the frame bitbuffer
713          */
714         if(do_mid_side) {
715                 FLAC__ChannelAssignment channel_assignment;
716
717                 assert(encoder->channels == 2);
718
719                 if(encoder->loose_mid_side_stereo && encoder->guts->loose_mid_side_stereo_frame_count > 0) {
720                         channel_assignment = (encoder->guts->last_channel_assignment == FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT? FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT : FLAC__CHANNEL_ASSIGNMENT_MID_SIDE);
721                 }
722                 else {
723                         unsigned bits[4]; /* WATCHOUT - indexed by FLAC__ChannelAssignment */
724                         unsigned min_bits;
725                         FLAC__ChannelAssignment ca;
726
727                         assert(do_independent && do_mid_side);
728
729                         /* We have to figure out which channel assignent results in the smallest frame */
730                         bits[FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT] = encoder->guts->best_subframe_bits         [0] + encoder->guts->best_subframe_bits         [1];
731                         bits[FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE  ] = encoder->guts->best_subframe_bits         [0] + encoder->guts->best_subframe_bits_mid_side[1];
732                         bits[FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE ] = encoder->guts->best_subframe_bits         [1] + encoder->guts->best_subframe_bits_mid_side[1];
733                         bits[FLAC__CHANNEL_ASSIGNMENT_MID_SIDE   ] = encoder->guts->best_subframe_bits_mid_side[0] + encoder->guts->best_subframe_bits_mid_side[1];
734
735                         for(channel_assignment = 0, min_bits = bits[0], ca = 1; ca <= 3; ca++) {
736                                 if(bits[ca] < min_bits) {
737                                         min_bits = bits[ca];
738                                         channel_assignment = ca;
739                                 }
740                         }
741                 }
742
743                 frame_header.channel_assignment = channel_assignment;
744
745                 if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame)) {
746                         encoder->state = FLAC__ENCODER_FRAMING_ERROR;
747                         return false;
748                 }
749
750                 switch(channel_assignment) {
751                         /* note that encoder_add_subframe_ sets the state for us in case of an error */
752                         case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
753                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [0][encoder->guts->best_subframe         [0]], &encoder->guts->frame))
754                                         return false;
755                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [1][encoder->guts->best_subframe         [1]], &encoder->guts->frame))
756                                         return false;
757                                 break;
758                         case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
759                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [0][encoder->guts->best_subframe         [0]], &encoder->guts->frame))
760                                         return false;
761                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample+1, &encoder->guts->subframe_workspace_mid_side[1][encoder->guts->best_subframe_mid_side[1]], &encoder->guts->frame))
762                                         return false;
763                                 break;
764                         case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
765                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample+1, &encoder->guts->subframe_workspace_mid_side[1][encoder->guts->best_subframe_mid_side[1]], &encoder->guts->frame))
766                                         return false;
767                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [1][encoder->guts->best_subframe         [1]], &encoder->guts->frame))
768                                         return false;
769                                 break;
770                         case FLAC__CHANNEL_ASSIGNMENT_MID_SIDE:
771                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace_mid_side[0][encoder->guts->best_subframe_mid_side[0]], &encoder->guts->frame))
772                                         return false;
773                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample+1, &encoder->guts->subframe_workspace_mid_side[1][encoder->guts->best_subframe_mid_side[1]], &encoder->guts->frame))
774                                         return false;
775                                 break;
776                         default:
777                                 assert(0);
778                 }
779         }
780         else {
781                 if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame)) {
782                         encoder->state = FLAC__ENCODER_FRAMING_ERROR;
783                         return false;
784                 }
785
786                 for(channel = 0; channel < encoder->channels; channel++) {
787                         if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample, &encoder->guts->subframe_workspace[channel][encoder->guts->best_subframe[channel]], &encoder->guts->frame)) {
788                                 /* the above function sets the state for us in case of an error */
789                                 return false;
790                         }
791                 }
792         }
793
794         if(encoder->loose_mid_side_stereo) {
795                 encoder->guts->loose_mid_side_stereo_frame_count++;
796                 if(encoder->guts->loose_mid_side_stereo_frame_count >= encoder->guts->loose_mid_side_stereo_frames)
797                         encoder->guts->loose_mid_side_stereo_frame_count = 0;
798         }
799
800         encoder->guts->last_channel_assignment = frame_header.channel_assignment;
801
802         return true;
803 }
804
805 bool encoder_process_subframe_(FLAC__Encoder *encoder, unsigned max_partition_order, bool verbatim_only, const FLAC__FrameHeader *frame_header, unsigned bits_per_sample, const int32 integer_signal[], const real real_signal[], FLAC__Subframe *subframe[2], int32 *residual[2], unsigned *best_subframe, unsigned *best_bits)
806 {
807         real fixed_residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1];
808         real lpc_residual_bits_per_sample;
809         real autoc[FLAC__MAX_LPC_ORDER+1];
810         real lp_coeff[FLAC__MAX_LPC_ORDER][FLAC__MAX_LPC_ORDER];
811         real lpc_error[FLAC__MAX_LPC_ORDER];
812         unsigned min_lpc_order, max_lpc_order, lpc_order;
813         unsigned min_fixed_order, max_fixed_order, guess_fixed_order, fixed_order;
814         unsigned min_qlp_coeff_precision, max_qlp_coeff_precision, qlp_coeff_precision;
815         unsigned rice_parameter;
816         unsigned _candidate_bits, _best_bits;
817         unsigned _best_subframe;
818
819         /* verbatim subframe is the baseline against which we measure other compressed subframes */
820         _best_subframe = 0;
821         _best_bits = encoder_evaluate_verbatim_subframe_(integer_signal, frame_header->blocksize, bits_per_sample, subframe[_best_subframe]);
822
823         if(!verbatim_only && frame_header->blocksize >= FLAC__MAX_FIXED_ORDER) {
824                 /* check for constant subframe */
825                 guess_fixed_order = FLAC__fixed_compute_best_predictor(integer_signal+FLAC__MAX_FIXED_ORDER, frame_header->blocksize-FLAC__MAX_FIXED_ORDER, fixed_residual_bits_per_sample);
826                 if(fixed_residual_bits_per_sample[1] == 0.0) {
827                         /* the above means integer_signal+FLAC__MAX_FIXED_ORDER is constant, now we just have to check the warmup samples */
828                         unsigned i, signal_is_constant = true;
829                         for(i = 1; i <= FLAC__MAX_FIXED_ORDER; i++) {
830                                 if(integer_signal[0] != integer_signal[i]) {
831                                         signal_is_constant = false;
832                                         break;
833                                 }
834                         }
835                         if(signal_is_constant) {
836                                 _candidate_bits = encoder_evaluate_constant_subframe_(integer_signal[0], bits_per_sample, subframe[!_best_subframe]);
837                                 if(_candidate_bits < _best_bits) {
838                                         _best_subframe = !_best_subframe;
839                                         _best_bits = _candidate_bits;
840                                 }
841                         }
842                 }
843                 else {
844                         /* encode fixed */
845                         if(encoder->do_exhaustive_model_search) {
846                                 min_fixed_order = 0;
847                                 max_fixed_order = FLAC__MAX_FIXED_ORDER;
848                         }
849                         else {
850                                 min_fixed_order = max_fixed_order = guess_fixed_order;
851                         }
852                         for(fixed_order = min_fixed_order; fixed_order <= max_fixed_order; fixed_order++) {
853                                 if(fixed_residual_bits_per_sample[fixed_order] >= (real)bits_per_sample)
854                                         continue; /* don't even try */
855                                 rice_parameter = (fixed_residual_bits_per_sample[fixed_order] > 0.0)? (unsigned)(fixed_residual_bits_per_sample[fixed_order]+0.5) : 0; /* 0.5 is for rounding */
856                                 rice_parameter++; /* to account for the signed->unsigned conversion during rice coding */
857                                 if(rice_parameter >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN))
858                                         rice_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
859                                 _candidate_bits = encoder_evaluate_fixed_subframe_(integer_signal, residual[!_best_subframe], encoder->guts->abs_residual, frame_header->blocksize, bits_per_sample, fixed_order, rice_parameter, max_partition_order, subframe[!_best_subframe]);
860                                 if(_candidate_bits < _best_bits) {
861                                         _best_subframe = !_best_subframe;
862                                         _best_bits = _candidate_bits;
863                                 }
864                         }
865
866                         /* encode lpc */
867                         if(encoder->max_lpc_order > 0) {
868                                 if(encoder->max_lpc_order >= frame_header->blocksize)
869                                         max_lpc_order = frame_header->blocksize-1;
870                                 else
871                                         max_lpc_order = encoder->max_lpc_order;
872                                 if(max_lpc_order > 0) {
873                                         FLAC__lpc_compute_autocorrelation(real_signal, frame_header->blocksize, max_lpc_order+1, autoc);
874                                         FLAC__lpc_compute_lp_coefficients(autoc, max_lpc_order, lp_coeff, lpc_error);
875                                         if(encoder->do_exhaustive_model_search) {
876                                                 min_lpc_order = 1;
877                                         }
878                                         else {
879                                                 unsigned guess_lpc_order = FLAC__lpc_compute_best_order(lpc_error, max_lpc_order, frame_header->blocksize, bits_per_sample);
880                                                 min_lpc_order = max_lpc_order = guess_lpc_order;
881                                         }
882                                         if(encoder->do_qlp_coeff_prec_search) {
883                                                 min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
884                                                 max_qlp_coeff_precision = min(32 - bits_per_sample - 1, (1u<<FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN)-1);
885                                         }
886                                         else {
887                                                 min_qlp_coeff_precision = max_qlp_coeff_precision = encoder->qlp_coeff_precision;
888                                         }
889                                         for(lpc_order = min_lpc_order; lpc_order <= max_lpc_order; lpc_order++) {
890                                                 lpc_residual_bits_per_sample = FLAC__lpc_compute_expected_bits_per_residual_sample(lpc_error[lpc_order-1], frame_header->blocksize-lpc_order);
891                                                 if(lpc_residual_bits_per_sample >= (real)bits_per_sample)
892                                                         continue; /* don't even try */
893                                                 rice_parameter = (lpc_residual_bits_per_sample > 0.0)? (unsigned)(lpc_residual_bits_per_sample+0.5) : 0; /* 0.5 is for rounding */
894                                                 rice_parameter++; /* to account for the signed->unsigned conversion during rice coding */
895                                                 if(rice_parameter >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN))
896                                                         rice_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
897                                                 for(qlp_coeff_precision = min_qlp_coeff_precision; qlp_coeff_precision <= max_qlp_coeff_precision; qlp_coeff_precision++) {
898                                                         _candidate_bits = encoder_evaluate_lpc_subframe_(integer_signal, residual[!_best_subframe], encoder->guts->abs_residual, lp_coeff[lpc_order-1], frame_header->blocksize, bits_per_sample, lpc_order, qlp_coeff_precision, rice_parameter, max_partition_order, subframe[!_best_subframe]);
899                                                         if(_candidate_bits > 0) { /* if == 0, there was a problem quantizing the lpcoeffs */
900                                                                 if(_candidate_bits < _best_bits) {
901                                                                         _best_subframe = !_best_subframe;
902                                                                         _best_bits = _candidate_bits;
903                                                                 }
904                                                         }
905                                                 }
906                                         }
907                                 }
908                         }
909                 }
910         }
911
912         *best_subframe = _best_subframe;
913         *best_bits = _best_bits;
914
915         return true;
916 }
917
918 bool encoder_add_subframe_(FLAC__Encoder *encoder, const FLAC__FrameHeader *frame_header, unsigned bits_per_sample, const FLAC__Subframe *subframe, FLAC__BitBuffer *frame)
919 {
920         switch(subframe->type) {
921                 case FLAC__SUBFRAME_TYPE_CONSTANT:
922                         if(!FLAC__subframe_add_constant(&(subframe->data.constant), bits_per_sample, frame)) {
923                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
924                                 return false;
925                         }
926                         break;
927                 case FLAC__SUBFRAME_TYPE_FIXED:
928                         if(!FLAC__subframe_add_fixed(&(subframe->data.fixed), frame_header->blocksize - subframe->data.fixed.order, bits_per_sample, frame)) {
929                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
930                                 return false;
931                         }
932                         break;
933                 case FLAC__SUBFRAME_TYPE_LPC:
934                         if(!FLAC__subframe_add_lpc(&(subframe->data.lpc), frame_header->blocksize - subframe->data.lpc.order, bits_per_sample, frame)) {
935                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
936                                 return false;
937                         }
938                         break;
939                 case FLAC__SUBFRAME_TYPE_VERBATIM:
940                         if(!FLAC__subframe_add_verbatim(&(subframe->data.verbatim), frame_header->blocksize, bits_per_sample, frame)) {
941                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
942                                 return false;
943                         }
944                         break;
945                 default:
946                         assert(0);
947         }
948
949         return true;
950 }
951
952 unsigned encoder_evaluate_constant_subframe_(const int32 signal, unsigned bits_per_sample, FLAC__Subframe *subframe)
953 {
954         subframe->type = FLAC__SUBFRAME_TYPE_CONSTANT;
955         subframe->data.constant.value = signal;
956
957         return FLAC__SUBFRAME_TYPE_LEN + bits_per_sample;
958 }
959
960 unsigned encoder_evaluate_fixed_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe)
961 {
962         unsigned i, residual_bits;
963         const unsigned residual_samples = blocksize - order;
964
965         FLAC__fixed_compute_residual(signal+order, residual_samples, order, residual);
966
967         subframe->type = FLAC__SUBFRAME_TYPE_FIXED;
968
969         subframe->data.fixed.entropy_coding_method.type = FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE;
970         subframe->data.fixed.residual = residual;
971
972         residual_bits = encoder_find_best_partition_order_(residual, abs_residual, residual_samples, order, rice_parameter, max_partition_order, &subframe->data.fixed.entropy_coding_method.data.partitioned_rice.order, subframe->data.fixed.entropy_coding_method.data.partitioned_rice.parameters);
973
974         subframe->data.fixed.order = order;
975         for(i = 0; i < order; i++)
976                 subframe->data.fixed.warmup[i] = signal[i];
977
978         return FLAC__SUBFRAME_TYPE_LEN + (order * bits_per_sample) + residual_bits;
979 }
980
981 unsigned encoder_evaluate_lpc_subframe_(const int32 signal[], int32 residual[], uint32 abs_residual[], const real lp_coeff[], unsigned blocksize, unsigned bits_per_sample, unsigned order, unsigned qlp_coeff_precision, unsigned rice_parameter, unsigned max_partition_order, FLAC__Subframe *subframe)
982 {
983         int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
984         unsigned i, residual_bits;
985         int quantization, ret;
986         const unsigned residual_samples = blocksize - order;
987
988         ret = FLAC__lpc_quantize_coefficients(lp_coeff, order, qlp_coeff_precision, bits_per_sample, qlp_coeff, &quantization);
989         if(ret != 0)
990                 return 0; /* this is a hack to indicate to the caller that we can't do lp at this order on this subframe */
991
992         FLAC__lpc_compute_residual_from_qlp_coefficients(signal+order, residual_samples, qlp_coeff, order, quantization, residual);
993
994         subframe->type = FLAC__SUBFRAME_TYPE_LPC;
995
996         subframe->data.lpc.entropy_coding_method.type = FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE;
997         subframe->data.lpc.residual = residual;
998
999         residual_bits = encoder_find_best_partition_order_(residual, abs_residual, residual_samples, order, rice_parameter, max_partition_order, &subframe->data.lpc.entropy_coding_method.data.partitioned_rice.order, subframe->data.lpc.entropy_coding_method.data.partitioned_rice.parameters);
1000
1001         subframe->data.lpc.order = order;
1002         subframe->data.lpc.qlp_coeff_precision = qlp_coeff_precision;
1003         subframe->data.lpc.quantization_level = quantization;
1004         memcpy(subframe->data.lpc.qlp_coeff, qlp_coeff, sizeof(int32)*FLAC__MAX_LPC_ORDER);
1005         for(i = 0; i < order; i++)
1006                 subframe->data.lpc.warmup[i] = signal[i];
1007
1008         return FLAC__SUBFRAME_TYPE_LEN + FLAC__SUBFRAME_LPC_QLP_COEFF_PRECISION_LEN + FLAC__SUBFRAME_LPC_QLP_SHIFT_LEN + (order * (qlp_coeff_precision + bits_per_sample)) + residual_bits;
1009 }
1010
1011 unsigned encoder_evaluate_verbatim_subframe_(const int32 signal[], unsigned blocksize, unsigned bits_per_sample, FLAC__Subframe *subframe)
1012 {
1013         subframe->type = FLAC__SUBFRAME_TYPE_VERBATIM;
1014
1015         subframe->data.verbatim.data = signal;
1016
1017         return FLAC__SUBFRAME_TYPE_LEN + (blocksize * bits_per_sample);
1018 }
1019
1020 unsigned encoder_find_best_partition_order_(const int32 residual[], uint32 abs_residual[], unsigned residual_samples, unsigned predictor_order, unsigned rice_parameter, unsigned max_partition_order, unsigned *best_partition_order, unsigned best_parameters[])
1021 {
1022         unsigned residual_bits, best_residual_bits = 0;
1023         unsigned i, partition_order;
1024         unsigned best_parameters_index = 0, parameters[2][1 << FLAC__MAX_RICE_PARTITION_ORDER];
1025         int32 r;
1026
1027         /* compute the abs(residual) for use later */
1028         for(i = 0; i < residual_samples; i++) {
1029                 r = residual[i];
1030                 abs_residual[i] = (uint32)(r<0? -r : r);
1031         }
1032
1033         for(partition_order = 0; partition_order <= max_partition_order; partition_order++) {
1034                 if(!encoder_set_partitioned_rice_(abs_residual, residual_samples, predictor_order, rice_parameter, partition_order, parameters[!best_parameters_index], &residual_bits)) {
1035                         assert(best_residual_bits != 0);
1036                         break;
1037                 }
1038                 if(best_residual_bits == 0 || residual_bits < best_residual_bits) {
1039                         best_residual_bits = residual_bits;
1040                         *best_partition_order = partition_order;
1041                         best_parameters_index = !best_parameters_index;
1042                 }
1043         }
1044         memcpy(best_parameters, parameters[best_parameters_index], sizeof(unsigned)*(1<<(*best_partition_order)));
1045
1046         return best_residual_bits;
1047 }
1048
1049 #ifdef ESTIMATE_RICE_BITS
1050 #undef ESTIMATE_RICE_BITS
1051 #endif
1052 #define ESTIMATE_RICE_BITS(value, parameter) ((value) >> (parameter))
1053
1054 bool encoder_set_partitioned_rice_(const uint32 abs_residual[], const unsigned residual_samples, const unsigned predictor_order, const unsigned rice_parameter, const unsigned partition_order, unsigned parameters[], unsigned *bits)
1055 {
1056         unsigned bits_ = FLAC__ENTROPY_CODING_METHOD_TYPE_LEN + FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN;
1057
1058         if(partition_order == 0) {
1059                 unsigned i;
1060 #ifdef ESTIMATE_RICE_BITS
1061                 const unsigned rice_parameter_estimate = rice_parameter-1;
1062                 bits_ += (1+rice_parameter) * residual_samples;
1063 #endif
1064                 parameters[0] = rice_parameter;
1065                 bits_ += FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN;
1066                 for(i = 0; i < residual_samples; i++)
1067 #ifdef ESTIMATE_RICE_BITS
1068                         bits_ += ESTIMATE_RICE_BITS(abs_residual[i], rice_parameter_estimate);
1069 #else
1070                         bits_ += FLAC__bitbuffer_rice_bits(residual[i], rice_parameter);
1071 #endif
1072         }
1073         else {
1074                 unsigned i, j, k = 0, k_last = 0;
1075                 unsigned mean, parameter, partition_samples;
1076                 const unsigned max_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
1077                 for(i = 0; i < (1u<<partition_order); i++) {
1078                         partition_samples = (residual_samples+predictor_order) >> partition_order;
1079                         if(i == 0) {
1080                                 if(partition_samples <= predictor_order)
1081                                         return false;
1082                                 else
1083                                         partition_samples -= predictor_order;
1084                         }
1085                         mean = partition_samples >> 1;
1086                         for(j = 0; j < partition_samples; j++, k++)
1087                                 mean += abs_residual[k];
1088                         mean /= partition_samples;
1089                         /* calc parameter = floor(log2(mean)) + 1 */
1090                         parameter = 0;
1091                         while(mean) {
1092                                 parameter++;
1093                                 mean >>= 1;
1094                         }
1095                         if(parameter > max_parameter)
1096                                 parameter = max_parameter;
1097                         parameters[i] = parameter;
1098                         bits_ += FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN;
1099 #ifdef ESTIMATE_RICE_BITS
1100                         bits_ += (1+parameter) * partition_samples;
1101                         --parameter;
1102 #endif
1103                         for(j = k_last; j < k; j++)
1104 #ifdef ESTIMATE_RICE_BITS
1105                                 bits_ += ESTIMATE_RICE_BITS(abs_residual[j], parameter);
1106 #else
1107                                 bits_ += FLAC__bitbuffer_rice_bits(residual[j], parameter);
1108 #endif
1109                         k_last = k;
1110                 }
1111         }
1112
1113         *bits = bits_;
1114         return true;
1115 }