cd01421e46b51e6137b11db768ad4628a89efdc3
[flac.git] / src / libFLAC / encoder.c
1 /* libFLAC - Free Lossless Audio Coder 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
250         assert(sizeof(int) >= 4); /* we want to die right away if this is not true */
251         assert(encoder != 0);
252         assert(write_callback != 0);
253         assert(metadata_callback != 0);
254         assert(encoder->state == FLAC__ENCODER_UNINITIALIZED);
255         assert(encoder->guts == 0);
256
257         encoder->state = FLAC__ENCODER_OK;
258
259         if(encoder->channels == 0 || encoder->channels > FLAC__MAX_CHANNELS)
260                 return encoder->state = FLAC__ENCODER_INVALID_NUMBER_OF_CHANNELS;
261
262         if(encoder->do_mid_side_stereo && encoder->channels != 2)
263                 return encoder->state = FLAC__ENCODER_MID_SIDE_CHANNELS_MISMATCH;
264
265         if(encoder->do_mid_side_stereo && encoder->bits_per_sample > 16)
266                 return encoder->state = FLAC__ENCODER_MID_SIDE_SAMPLE_SIZE_MISMATCH;
267
268         if(encoder->loose_mid_side_stereo && !encoder->do_mid_side_stereo)
269                 return encoder->state = FLAC__ENCODER_ILLEGAL_MID_SIDE_FORCE;
270
271         if(encoder->bits_per_sample == 0 || encoder->bits_per_sample > FLAC__MAX_BITS_PER_SAMPLE)
272                 return encoder->state = FLAC__ENCODER_INVALID_BITS_PER_SAMPLE;
273
274         if(encoder->sample_rate == 0 || encoder->sample_rate > FLAC__MAX_SAMPLE_RATE)
275                 return encoder->state = FLAC__ENCODER_INVALID_SAMPLE_RATE;
276
277         if(encoder->blocksize < FLAC__MIN_BLOCK_SIZE || encoder->blocksize > FLAC__MAX_BLOCK_SIZE)
278                 return encoder->state = FLAC__ENCODER_INVALID_BLOCK_SIZE;
279
280         if(encoder->blocksize < encoder->max_lpc_order)
281                 return encoder->state = FLAC__ENCODER_BLOCK_SIZE_TOO_SMALL_FOR_LPC_ORDER;
282
283         if(encoder->qlp_coeff_precision == 0) {
284                 if(encoder->bits_per_sample < 16) {
285                         /* @@@ need some data about how to set this here w.r.t. blocksize and sample rate */
286                         /* @@@ until then we'll make a guess */
287                         encoder->qlp_coeff_precision = max(5, 2 + encoder->bits_per_sample / 2);
288                 }
289                 else if(encoder->bits_per_sample == 16) {
290                         if(encoder->blocksize <= 192)
291                                 encoder->qlp_coeff_precision = 7;
292                         else if(encoder->blocksize <= 384)
293                                 encoder->qlp_coeff_precision = 8;
294                         else if(encoder->blocksize <= 576)
295                                 encoder->qlp_coeff_precision = 9;
296                         else if(encoder->blocksize <= 1152)
297                                 encoder->qlp_coeff_precision = 10;
298                         else if(encoder->blocksize <= 2304)
299                                 encoder->qlp_coeff_precision = 11;
300                         else if(encoder->blocksize <= 4608)
301                                 encoder->qlp_coeff_precision = 12;
302                         else
303                                 encoder->qlp_coeff_precision = 13;
304                 }
305                 else {
306                         encoder->qlp_coeff_precision = min(13, 8*sizeof(int32) - encoder->bits_per_sample - 1);
307                 }
308         }
309         else if(encoder->qlp_coeff_precision < FLAC__MIN_QLP_COEFF_PRECISION || encoder->qlp_coeff_precision + encoder->bits_per_sample >= 8*sizeof(uint32))
310                 return encoder->state = FLAC__ENCODER_INVALID_QLP_COEFF_PRECISION;
311
312         if(encoder->streamable_subset) {
313                 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)
314                         return encoder->state = FLAC__ENCODER_NOT_STREAMABLE;
315                 if(encoder->sample_rate > 655350)
316                         return encoder->state = FLAC__ENCODER_NOT_STREAMABLE;
317         }
318
319         if(encoder->rice_optimization_level >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN))
320                 encoder->rice_optimization_level = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN) - 1;
321
322         encoder->guts = (FLAC__EncoderPrivate*)malloc(sizeof(FLAC__EncoderPrivate));
323         if(encoder->guts == 0)
324                 return encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
325
326         encoder->guts->input_capacity = 0;
327         for(i = 0; i < encoder->channels; i++) {
328                 encoder->guts->integer_signal[i] = 0;
329                 encoder->guts->real_signal[i] = 0;
330         }
331         for(i = 0; i < 2; i++) {
332                 encoder->guts->integer_signal_mid_side[i] = 0;
333                 encoder->guts->real_signal_mid_side[i] = 0;
334         }
335         for(i = 0; i < encoder->channels; i++) {
336                 encoder->guts->residual_workspace[i][0] = encoder->guts->residual_workspace[i][1] = 0;
337                 encoder->guts->best_subframe[i] = 0;
338         }
339         for(i = 0; i < 2; i++) {
340                 encoder->guts->residual_workspace_mid_side[i][0] = encoder->guts->residual_workspace_mid_side[i][1] = 0;
341                 encoder->guts->best_subframe_mid_side[i] = 0;
342         }
343         for(i = 0; i < encoder->channels; i++) {
344                 encoder->guts->subframe_workspace_ptr[i][0] = &encoder->guts->subframe_workspace[i][0];
345                 encoder->guts->subframe_workspace_ptr[i][1] = &encoder->guts->subframe_workspace[i][1];
346         }
347         for(i = 0; i < 2; i++) {
348                 encoder->guts->subframe_workspace_ptr_mid_side[i][0] = &encoder->guts->subframe_workspace_mid_side[i][0];
349                 encoder->guts->subframe_workspace_ptr_mid_side[i][1] = &encoder->guts->subframe_workspace_mid_side[i][1];
350         }
351         encoder->guts->abs_residual = 0;
352         encoder->guts->current_frame_can_do_mid_side = true;
353         encoder->guts->loose_mid_side_stereo_frames_exact = (double)encoder->sample_rate * 0.4 / (double)encoder->blocksize;
354         encoder->guts->loose_mid_side_stereo_frames = (unsigned)(encoder->guts->loose_mid_side_stereo_frames_exact + 0.5);
355         if(encoder->guts->loose_mid_side_stereo_frames == 0)
356                 encoder->guts->loose_mid_side_stereo_frames = 1;
357         encoder->guts->loose_mid_side_stereo_frame_count = 0;
358         encoder->guts->current_sample_number = 0;
359         encoder->guts->current_frame_number = 0;
360
361         if(!encoder_resize_buffers_(encoder, encoder->blocksize)) {
362                 /* the above function sets the state for us in case of an error */
363                 return encoder->state;
364         }
365         FLAC__bitbuffer_init(&encoder->guts->frame);
366         encoder->guts->write_callback = write_callback;
367         encoder->guts->metadata_callback = metadata_callback;
368         encoder->guts->client_data = client_data;
369
370         /*
371          * write the stream header
372          */
373         if(!FLAC__bitbuffer_clear(&encoder->guts->frame))
374                 return encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
375
376         if(!FLAC__bitbuffer_write_raw_uint32(&encoder->guts->frame, FLAC__STREAM_SYNC, FLAC__STREAM_SYNC_LEN))
377                 return encoder->state = FLAC__ENCODER_FRAMING_ERROR;
378
379         encoder->guts->metadata.type = FLAC__METADATA_TYPE_ENCODING;
380         encoder->guts->metadata.is_last = true;
381         encoder->guts->metadata.length = FLAC__STREAM_METADATA_ENCODING_LENGTH;
382         encoder->guts->metadata.data.encoding.min_blocksize = encoder->blocksize; /* this encoder uses the same blocksize for the whole stream */
383         encoder->guts->metadata.data.encoding.max_blocksize = encoder->blocksize;
384         encoder->guts->metadata.data.encoding.min_framesize = 0; /* we don't know this yet; have to fill it in later */
385         encoder->guts->metadata.data.encoding.max_framesize = 0; /* we don't know this yet; have to fill it in later */
386         encoder->guts->metadata.data.encoding.sample_rate = encoder->sample_rate;
387         encoder->guts->metadata.data.encoding.channels = encoder->channels;
388         encoder->guts->metadata.data.encoding.bits_per_sample = encoder->bits_per_sample;
389         encoder->guts->metadata.data.encoding.total_samples = encoder->total_samples_estimate; /* we will replace this later with the real total */
390         memset(encoder->guts->metadata.data.encoding.md5sum, 0, 16); /* we don't know this yet; have to fill it in later */
391         MD5Init(&encoder->guts->md5context);
392         if(!FLAC__add_metadata_block(&encoder->guts->metadata, &encoder->guts->frame))
393                 return encoder->state = FLAC__ENCODER_FRAMING_ERROR;
394
395         assert(encoder->guts->frame.bits == 0); /* assert that we're byte-aligned before writing */
396         assert(encoder->guts->frame.total_consumed_bits == 0); /* assert that no reading of the buffer was done */
397         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)
398                 return encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_WRITING;
399
400         /* now that the metadata block is written, we can init this to an absurdly-high value... */
401         encoder->guts->metadata.data.encoding.min_framesize = (1u << FLAC__STREAM_METADATA_ENCODING_MIN_FRAME_SIZE_LEN) - 1;
402         /* ... and clear this to 0 */
403         encoder->guts->metadata.data.encoding.total_samples = 0;
404
405         return encoder->state;
406 }
407
408 void FLAC__encoder_finish(FLAC__Encoder *encoder)
409 {
410         unsigned i, channel;
411
412         assert(encoder != 0);
413         if(encoder->state == FLAC__ENCODER_UNINITIALIZED)
414                 return;
415         if(encoder->guts->current_sample_number != 0) {
416                 encoder->blocksize = encoder->guts->current_sample_number;
417                 encoder_process_frame_(encoder, true); /* true => is last frame */
418         }
419         MD5Final(encoder->guts->metadata.data.encoding.md5sum, &encoder->guts->md5context);
420         encoder->guts->metadata_callback(encoder, &encoder->guts->metadata, encoder->guts->client_data);
421         if(encoder->guts != 0) {
422                 for(i = 0; i < encoder->channels; i++) {
423                         if(encoder->guts->integer_signal[i] != 0) {
424                                 free(encoder->guts->integer_signal[i]);
425                                 encoder->guts->integer_signal[i] = 0;
426                         }
427                         if(encoder->guts->real_signal[i] != 0) {
428                                 free(encoder->guts->real_signal[i]);
429                                 encoder->guts->real_signal[i] = 0;
430                         }
431                 }
432                 for(i = 0; i < 2; i++) {
433                         if(encoder->guts->integer_signal_mid_side[i] != 0) {
434                                 free(encoder->guts->integer_signal_mid_side[i]);
435                                 encoder->guts->integer_signal_mid_side[i] = 0;
436                         }
437                         if(encoder->guts->real_signal_mid_side[i] != 0) {
438                                 free(encoder->guts->real_signal_mid_side[i]);
439                                 encoder->guts->real_signal_mid_side[i] = 0;
440                         }
441                 }
442                 for(channel = 0; channel < encoder->channels; channel++) {
443                         for(i = 0; i < 2; i++) {
444                                 if(encoder->guts->residual_workspace[channel][i] != 0) {
445                                         free(encoder->guts->residual_workspace[channel][i]);
446                                         encoder->guts->residual_workspace[channel][i] = 0;
447                                 }
448                         }
449                 }
450                 for(channel = 0; channel < 2; channel++) {
451                         for(i = 0; i < 2; i++) {
452                                 if(encoder->guts->residual_workspace_mid_side[channel][i] != 0) {
453                                         free(encoder->guts->residual_workspace_mid_side[channel][i]);
454                                         encoder->guts->residual_workspace_mid_side[channel][i] = 0;
455                                 }
456                         }
457                 }
458                 if(encoder->guts->abs_residual != 0) {
459                         free(encoder->guts->abs_residual);
460                         encoder->guts->abs_residual = 0;
461                 }
462                 FLAC__bitbuffer_free(&encoder->guts->frame);
463                 free(encoder->guts);
464                 encoder->guts = 0;
465         }
466         encoder->state = FLAC__ENCODER_UNINITIALIZED;
467 }
468
469 bool FLAC__encoder_process(FLAC__Encoder *encoder, const int32 *buf[], unsigned samples)
470 {
471         unsigned i, j, channel;
472         int32 x, mid, side;
473         const bool ms = encoder->do_mid_side_stereo && encoder->channels == 2;
474         const int32 min_side = -((int64)1 << (encoder->bits_per_sample-1));
475         const int32 max_side =  ((int64)1 << (encoder->bits_per_sample-1)) - 1;
476
477         assert(encoder != 0);
478         assert(encoder->state == FLAC__ENCODER_OK);
479
480         j = 0;
481         do {
482                 for(i = encoder->guts->current_sample_number; i < encoder->blocksize && j < samples; i++, j++) {
483                         for(channel = 0; channel < encoder->channels; channel++) {
484                                 x = buf[channel][j];
485                                 encoder->guts->integer_signal[channel][i] = x;
486                                 encoder->guts->real_signal[channel][i] = (real)x;
487                         }
488                         if(ms && encoder->guts->current_frame_can_do_mid_side) {
489                                 side = buf[0][j] - buf[1][j];
490                                 if(side < min_side || side > max_side) {
491                                         encoder->guts->current_frame_can_do_mid_side = false;
492                                 }
493                                 else {
494                                         mid = (buf[0][j] + buf[1][j]) >> 1; /* NOTE: not the same as 'mid = (buf[0][j] + buf[1][j]) / 2' ! */
495                                         encoder->guts->integer_signal_mid_side[0][i] = mid;
496                                         encoder->guts->integer_signal_mid_side[1][i] = side;
497                                         encoder->guts->real_signal_mid_side[0][i] = (real)mid;
498                                         encoder->guts->real_signal_mid_side[1][i] = (real)side;
499                                 }
500                         }
501                         encoder->guts->current_sample_number++;
502                 }
503                 if(i == encoder->blocksize) {
504                         if(!encoder_process_frame_(encoder, false)) /* false => not last frame */
505                                 return false;
506                 }
507         } while(j < samples);
508
509         return true;
510 }
511
512 /* 'samples' is channel-wide samples, e.g. for 1 second at 44100Hz, 'samples' = 44100 regardless of the number of channels */
513 bool FLAC__encoder_process_interleaved(FLAC__Encoder *encoder, const int32 buf[], unsigned samples)
514 {
515         unsigned i, j, k, channel;
516         int32 x, left = 0, mid, side;
517         const bool ms = encoder->do_mid_side_stereo && encoder->channels == 2;
518         const int32 min_side = -((int64)1 << (encoder->bits_per_sample-1));
519         const int32 max_side =  ((int64)1 << (encoder->bits_per_sample-1)) - 1;
520
521         assert(encoder != 0);
522         assert(encoder->state == FLAC__ENCODER_OK);
523
524         j = k = 0;
525         do {
526                 for(i = encoder->guts->current_sample_number; i < encoder->blocksize && j < samples; i++, j++, k++) {
527                         for(channel = 0; channel < encoder->channels; channel++, k++) {
528                                 x = buf[k];
529                                 encoder->guts->integer_signal[channel][i] = x;
530                                 encoder->guts->real_signal[channel][i] = (real)x;
531                                 if(ms && encoder->guts->current_frame_can_do_mid_side) {
532                                         if(channel == 0) {
533                                                 left = x;
534                                         }
535                                         else {
536                                                 side = left - x;
537                                                 if(side < min_side || side > max_side) {
538                                                         encoder->guts->current_frame_can_do_mid_side = false;
539                                                 }
540                                                 else {
541                                                         mid = (left + x) >> 1; /* NOTE: not the same as 'mid = (left + x) / 2' ! */
542                                                         encoder->guts->integer_signal_mid_side[0][i] = mid;
543                                                         encoder->guts->integer_signal_mid_side[1][i] = side;
544                                                         encoder->guts->real_signal_mid_side[0][i] = (real)mid;
545                                                         encoder->guts->real_signal_mid_side[1][i] = (real)side;
546                                                 }
547                                         }
548                                 }
549                         }
550                         encoder->guts->current_sample_number++;
551                 }
552                 if(i == encoder->blocksize) {
553                         if(!encoder_process_frame_(encoder, false)) /* false => not last frame */
554                                 return false;
555                 }
556         } while(j < samples);
557
558         return true;
559 }
560
561 bool encoder_process_frame_(FLAC__Encoder *encoder, bool is_last_frame)
562 {
563         assert(encoder->state == FLAC__ENCODER_OK);
564
565         /*
566          * Accumulate raw signal to the MD5 signature
567          */
568         if(!FLAC__MD5Accumulate(&encoder->guts->md5context, encoder->guts->integer_signal, encoder->channels, encoder->blocksize, (encoder->bits_per_sample+7) / 8)) {
569                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
570                 return false;
571         }
572
573         /*
574          * Process the frame header and subframes into the frame bitbuffer
575          */
576         if(!encoder_process_subframes_(encoder, is_last_frame)) {
577                 /* the above function sets the state for us in case of an error */
578                 return false;
579         }
580
581         /*
582          * Zero-pad the frame to a byte_boundary
583          */
584         if(!FLAC__bitbuffer_zero_pad_to_byte_boundary(&encoder->guts->frame)) {
585                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
586                 return false;
587         }
588
589         /*
590          * Write it
591          */
592         assert(encoder->guts->frame.bits == 0); /* assert that we're byte-aligned before writing */
593         assert(encoder->guts->frame.total_consumed_bits == 0); /* assert that no reading of the buffer was done */
594         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) {
595                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_WRITING;
596                 return false;
597         }
598
599         /*
600          * Get ready for the next frame
601          */
602         encoder->guts->current_frame_can_do_mid_side = true;
603         encoder->guts->current_sample_number = 0;
604         encoder->guts->current_frame_number++;
605         encoder->guts->metadata.data.encoding.total_samples += (uint64)encoder->blocksize;
606         encoder->guts->metadata.data.encoding.min_framesize = min(encoder->guts->frame.bytes, encoder->guts->metadata.data.encoding.min_framesize);
607         encoder->guts->metadata.data.encoding.max_framesize = max(encoder->guts->frame.bytes, encoder->guts->metadata.data.encoding.max_framesize);
608
609         return true;
610 }
611
612 bool encoder_process_subframes_(FLAC__Encoder *encoder, bool is_last_frame)
613 {
614         FLAC__FrameHeader frame_header;
615         unsigned channel, max_partition_order;
616         bool do_independent, do_mid_side;
617
618         /*
619          * Calculate the max Rice partition order
620          */
621         if(is_last_frame) {
622                 max_partition_order = 0;
623         }
624         else {
625                 unsigned limit = 0, b = encoder->blocksize;
626                 while(!(b & 1)) {
627                         limit++;
628                         b >>= 1;
629                 }
630                 max_partition_order = min(encoder->rice_optimization_level, limit);
631         }
632
633         /*
634          * Setup the frame
635          */
636         if(!FLAC__bitbuffer_clear(&encoder->guts->frame)) {
637                 encoder->state = FLAC__ENCODER_MEMORY_ALLOCATION_ERROR;
638                 return false;
639         }
640         frame_header.blocksize = encoder->blocksize;
641         frame_header.sample_rate = encoder->sample_rate;
642         frame_header.channels = encoder->channels;
643         frame_header.channel_assignment = FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT; /* the default unless the encoder determines otherwise */
644         frame_header.bits_per_sample = encoder->bits_per_sample;
645         frame_header.number.frame_number = encoder->guts->current_frame_number;
646
647         /*
648          * Figure out what channel assignments to try
649          */
650         if(encoder->do_mid_side_stereo) {
651                 if(encoder->loose_mid_side_stereo) {
652                         if(encoder->guts->loose_mid_side_stereo_frame_count == 0) {
653                                 do_independent = true;
654                                 do_mid_side = true;
655                         }
656                         else {
657                                 do_independent = (encoder->guts->last_channel_assignment == FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT);
658                                 do_mid_side = !do_independent;
659                         }
660                 }
661                 else {
662                         do_independent = true;
663                         do_mid_side = true;
664                 }
665         }
666         else {
667                 do_independent = true;
668                 do_mid_side = false;
669         }
670         if(do_mid_side && !encoder->guts->current_frame_can_do_mid_side) {
671                 do_independent = true;
672                 do_mid_side = false;
673         }
674
675         assert(do_independent || do_mid_side);
676
677         /*
678          * First do a normal encoding pass of each independent channel
679          */
680         if(do_independent) {
681                 for(channel = 0; channel < encoder->channels; channel++) {
682                         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))
683                                 return false;
684                 }
685         }
686
687         /*
688          * Now do mid and side channels if requested
689          */
690         if(do_mid_side) {
691                 assert(encoder->channels == 2);
692
693                 for(channel = 0; channel < 2; channel++) {
694                         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))
695                                 return false;
696                 }
697         }
698
699         /*
700          * Compose the frame bitbuffer
701          */
702         if(do_mid_side) {
703                 FLAC__ChannelAssignment channel_assignment;
704
705                 assert(encoder->channels == 2);
706
707                 if(encoder->loose_mid_side_stereo && encoder->guts->loose_mid_side_stereo_frame_count > 0) {
708                         channel_assignment = (encoder->guts->last_channel_assignment == FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT? FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT : FLAC__CHANNEL_ASSIGNMENT_MID_SIDE);
709                 }
710                 else {
711                         unsigned bits[4]; /* WATCHOUT - indexed by FLAC__ChannelAssignment */
712                         unsigned min_bits;
713                         FLAC__ChannelAssignment ca;
714
715                         assert(do_independent && do_mid_side);
716
717                         /* We have to figure out which channel assignent results in the smallest frame */
718                         bits[FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT] = encoder->guts->best_subframe_bits         [0] + encoder->guts->best_subframe_bits         [1];
719                         bits[FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE  ] = encoder->guts->best_subframe_bits         [0] + encoder->guts->best_subframe_bits_mid_side[1];
720                         bits[FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE ] = encoder->guts->best_subframe_bits         [1] + encoder->guts->best_subframe_bits_mid_side[1];
721                         bits[FLAC__CHANNEL_ASSIGNMENT_MID_SIDE   ] = encoder->guts->best_subframe_bits_mid_side[0] + encoder->guts->best_subframe_bits_mid_side[1];
722
723                         for(channel_assignment = 0, min_bits = bits[0], ca = 1; ca <= 3; ca++) {
724                                 if(bits[ca] < min_bits) {
725                                         min_bits = bits[ca];
726                                         channel_assignment = ca;
727                                 }
728                         }
729                 }
730
731                 frame_header.channel_assignment = channel_assignment;
732
733                 if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame)) {
734                         encoder->state = FLAC__ENCODER_FRAMING_ERROR;
735                         return false;
736                 }
737
738                 switch(channel_assignment) {
739                         /* note that encoder_add_subframe_ sets the state for us in case of an error */
740                         case FLAC__CHANNEL_ASSIGNMENT_INDEPENDENT:
741                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [0][encoder->guts->best_subframe         [0]], &encoder->guts->frame))
742                                         return false;
743                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [1][encoder->guts->best_subframe         [1]], &encoder->guts->frame))
744                                         return false;
745                                 break;
746                         case FLAC__CHANNEL_ASSIGNMENT_LEFT_SIDE:
747                                 if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample  , &encoder->guts->subframe_workspace         [0][encoder->guts->best_subframe         [0]], &encoder->guts->frame))
748                                         return false;
749                                 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))
750                                         return false;
751                                 break;
752                         case FLAC__CHANNEL_ASSIGNMENT_RIGHT_SIDE:
753                                 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))
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_MID_SIDE:
759                                 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))
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                         default:
765                                 assert(0);
766                 }
767         }
768         else {
769                 if(!FLAC__frame_add_header(&frame_header, encoder->streamable_subset, is_last_frame, &encoder->guts->frame)) {
770                         encoder->state = FLAC__ENCODER_FRAMING_ERROR;
771                         return false;
772                 }
773
774                 for(channel = 0; channel < encoder->channels; channel++) {
775                         if(!encoder_add_subframe_(encoder, &frame_header, encoder->bits_per_sample, &encoder->guts->subframe_workspace[channel][encoder->guts->best_subframe[channel]], &encoder->guts->frame)) {
776                                 /* the above function sets the state for us in case of an error */
777                                 return false;
778                         }
779                 }
780         }
781
782         if(encoder->loose_mid_side_stereo) {
783                 encoder->guts->loose_mid_side_stereo_frame_count++;
784                 if(encoder->guts->loose_mid_side_stereo_frame_count >= encoder->guts->loose_mid_side_stereo_frames)
785                         encoder->guts->loose_mid_side_stereo_frame_count = 0;
786         }
787
788         encoder->guts->last_channel_assignment = frame_header.channel_assignment;
789
790         return true;
791 }
792
793 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)
794 {
795         real fixed_residual_bits_per_sample[FLAC__MAX_FIXED_ORDER+1];
796         real lpc_residual_bits_per_sample;
797         real autoc[FLAC__MAX_LPC_ORDER+1];
798         real lp_coeff[FLAC__MAX_LPC_ORDER][FLAC__MAX_LPC_ORDER];
799         real lpc_error[FLAC__MAX_LPC_ORDER];
800         unsigned min_lpc_order, max_lpc_order, lpc_order;
801         unsigned min_fixed_order, max_fixed_order, guess_fixed_order, fixed_order;
802         unsigned min_qlp_coeff_precision, max_qlp_coeff_precision, qlp_coeff_precision;
803         unsigned rice_parameter;
804         unsigned _candidate_bits, _best_bits;
805         unsigned _best_subframe;
806
807         /* verbatim subframe is the baseline against which we measure other compressed subframes */
808         _best_subframe = 0;
809         _best_bits = encoder_evaluate_verbatim_subframe_(integer_signal, frame_header->blocksize, bits_per_sample, subframe[_best_subframe]);
810
811         if(!verbatim_only && frame_header->blocksize >= FLAC__MAX_FIXED_ORDER) {
812                 /* check for constant subframe */
813                 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);
814                 if(fixed_residual_bits_per_sample[1] == 0.0) {
815                         /* the above means integer_signal+FLAC__MAX_FIXED_ORDER is constant, now we just have to check the warmup samples */
816                         unsigned i, signal_is_constant = true;
817                         for(i = 1; i <= FLAC__MAX_FIXED_ORDER; i++) {
818                                 if(integer_signal[0] != integer_signal[i]) {
819                                         signal_is_constant = false;
820                                         break;
821                                 }
822                         }
823                         if(signal_is_constant) {
824                                 _candidate_bits = encoder_evaluate_constant_subframe_(integer_signal[0], bits_per_sample, subframe[!_best_subframe]);
825                                 if(_candidate_bits < _best_bits) {
826                                         _best_subframe = !_best_subframe;
827                                         _best_bits = _candidate_bits;
828                                 }
829                         }
830                 }
831                 else {
832                         /* encode fixed */
833                         if(encoder->do_exhaustive_model_search) {
834                                 min_fixed_order = 0;
835                                 max_fixed_order = FLAC__MAX_FIXED_ORDER;
836                         }
837                         else {
838                                 min_fixed_order = max_fixed_order = guess_fixed_order;
839                         }
840                         for(fixed_order = min_fixed_order; fixed_order <= max_fixed_order; fixed_order++) {
841                                 if(fixed_residual_bits_per_sample[fixed_order] >= (real)bits_per_sample)
842                                         continue; /* don't even try */
843                                 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 */
844                                 rice_parameter++; /* to account for the signed->unsigned conversion during rice coding */
845                                 if(rice_parameter >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN))
846                                         rice_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
847                                 _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]);
848                                 if(_candidate_bits < _best_bits) {
849                                         _best_subframe = !_best_subframe;
850                                         _best_bits = _candidate_bits;
851                                 }
852                         }
853
854                         /* encode lpc */
855                         if(encoder->max_lpc_order > 0) {
856                                 if(encoder->max_lpc_order >= frame_header->blocksize)
857                                         max_lpc_order = frame_header->blocksize-1;
858                                 else
859                                         max_lpc_order = encoder->max_lpc_order;
860                                 if(max_lpc_order > 0) {
861                                         FLAC__lpc_compute_autocorrelation(real_signal, frame_header->blocksize, max_lpc_order+1, autoc);
862                                         FLAC__lpc_compute_lp_coefficients(autoc, max_lpc_order, lp_coeff, lpc_error);
863                                         if(encoder->do_exhaustive_model_search) {
864                                                 min_lpc_order = 1;
865                                         }
866                                         else {
867                                                 unsigned guess_lpc_order = FLAC__lpc_compute_best_order(lpc_error, max_lpc_order, frame_header->blocksize, bits_per_sample);
868                                                 min_lpc_order = max_lpc_order = guess_lpc_order;
869                                         }
870                                         if(encoder->do_qlp_coeff_prec_search) {
871                                                 min_qlp_coeff_precision = FLAC__MIN_QLP_COEFF_PRECISION;
872                                                 max_qlp_coeff_precision = 32 - bits_per_sample - 1;
873                                         }
874                                         else {
875                                                 min_qlp_coeff_precision = max_qlp_coeff_precision = encoder->qlp_coeff_precision;
876                                         }
877                                         for(lpc_order = min_lpc_order; lpc_order <= max_lpc_order; lpc_order++) {
878                                                 lpc_residual_bits_per_sample = FLAC__lpc_compute_expected_bits_per_residual_sample(lpc_error[lpc_order-1], frame_header->blocksize-lpc_order);
879                                                 if(lpc_residual_bits_per_sample >= (real)bits_per_sample)
880                                                         continue; /* don't even try */
881                                                 rice_parameter = (lpc_residual_bits_per_sample > 0.0)? (unsigned)(lpc_residual_bits_per_sample+0.5) : 0; /* 0.5 is for rounding */
882                                                 rice_parameter++; /* to account for the signed->unsigned conversion during rice coding */
883                                                 if(rice_parameter >= (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN))
884                                                         rice_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
885                                                 for(qlp_coeff_precision = min_qlp_coeff_precision; qlp_coeff_precision <= max_qlp_coeff_precision; qlp_coeff_precision++) {
886                                                         _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]);
887                                                         if(_candidate_bits > 0) { /* if == 0, there was a problem quantizing the lpcoeffs */
888                                                                 if(_candidate_bits < _best_bits) {
889                                                                         _best_subframe = !_best_subframe;
890                                                                         _best_bits = _candidate_bits;
891                                                                 }
892                                                         }
893                                                 }
894                                         }
895                                 }
896                         }
897                 }
898         }
899
900         *best_subframe = _best_subframe;
901         *best_bits = _best_bits;
902
903         return true;
904 }
905
906 bool encoder_add_subframe_(FLAC__Encoder *encoder, const FLAC__FrameHeader *frame_header, unsigned bits_per_sample, const FLAC__Subframe *subframe, FLAC__BitBuffer *frame)
907 {
908         switch(subframe->type) {
909                 case FLAC__SUBFRAME_TYPE_CONSTANT:
910                         if(!FLAC__subframe_add_constant(&(subframe->data.constant), bits_per_sample, frame)) {
911                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
912                                 return false;
913                         }
914                         break;
915                 case FLAC__SUBFRAME_TYPE_FIXED:
916                         if(!FLAC__subframe_add_fixed(&(subframe->data.fixed), frame_header->blocksize - subframe->data.fixed.order, bits_per_sample, frame)) {
917                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
918                                 return false;
919                         }
920                         break;
921                 case FLAC__SUBFRAME_TYPE_LPC:
922                         if(!FLAC__subframe_add_lpc(&(subframe->data.lpc), frame_header->blocksize - subframe->data.lpc.order, bits_per_sample, frame)) {
923                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
924                                 return false;
925                         }
926                         break;
927                 case FLAC__SUBFRAME_TYPE_VERBATIM:
928                         if(!FLAC__subframe_add_verbatim(&(subframe->data.verbatim), frame_header->blocksize, bits_per_sample, frame)) {
929                                 encoder->state = FLAC__ENCODER_FATAL_ERROR_WHILE_ENCODING;
930                                 return false;
931                         }
932                         break;
933                 default:
934                         assert(0);
935         }
936
937         return true;
938 }
939
940 unsigned encoder_evaluate_constant_subframe_(const int32 signal, unsigned bits_per_sample, FLAC__Subframe *subframe)
941 {
942         subframe->type = FLAC__SUBFRAME_TYPE_CONSTANT;
943         subframe->data.constant.value = signal;
944
945         return FLAC__SUBFRAME_TYPE_LEN + bits_per_sample;
946 }
947
948 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)
949 {
950         unsigned i, residual_bits;
951         const unsigned residual_samples = blocksize - order;
952
953         FLAC__fixed_compute_residual(signal+order, residual_samples, order, residual);
954
955         subframe->type = FLAC__SUBFRAME_TYPE_FIXED;
956
957         subframe->data.fixed.entropy_coding_method.type = FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE;
958         subframe->data.fixed.residual = residual;
959
960         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);
961
962         subframe->data.fixed.order = order;
963         for(i = 0; i < order; i++)
964                 subframe->data.fixed.warmup[i] = signal[i];
965
966         return FLAC__SUBFRAME_TYPE_LEN + (order * bits_per_sample) + residual_bits;
967 }
968
969 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)
970 {
971         int32 qlp_coeff[FLAC__MAX_LPC_ORDER];
972         unsigned i, residual_bits;
973         int quantization, ret;
974         const unsigned residual_samples = blocksize - order;
975
976         ret = FLAC__lpc_quantize_coefficients(lp_coeff, order, qlp_coeff_precision, bits_per_sample, qlp_coeff, &quantization);
977         if(ret != 0)
978                 return 0; /* this is a hack to indicate to the caller that we can't do lp at this order on this subframe */
979
980         FLAC__lpc_compute_residual_from_qlp_coefficients(signal+order, residual_samples, qlp_coeff, order, quantization, residual);
981
982         subframe->type = FLAC__SUBFRAME_TYPE_LPC;
983
984         subframe->data.lpc.entropy_coding_method.type = FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE;
985         subframe->data.lpc.residual = residual;
986
987         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);
988
989         subframe->data.lpc.order = order;
990         subframe->data.lpc.qlp_coeff_precision = qlp_coeff_precision;
991         subframe->data.lpc.quantization_level = quantization;
992         memcpy(subframe->data.lpc.qlp_coeff, qlp_coeff, sizeof(int32)*FLAC__MAX_LPC_ORDER);
993         for(i = 0; i < order; i++)
994                 subframe->data.lpc.warmup[i] = signal[i];
995
996         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;
997 }
998
999 unsigned encoder_evaluate_verbatim_subframe_(const int32 signal[], unsigned blocksize, unsigned bits_per_sample, FLAC__Subframe *subframe)
1000 {
1001         subframe->type = FLAC__SUBFRAME_TYPE_VERBATIM;
1002
1003         subframe->data.verbatim.data = signal;
1004
1005         return FLAC__SUBFRAME_TYPE_LEN + (blocksize * bits_per_sample);
1006 }
1007
1008 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[])
1009 {
1010         unsigned residual_bits, best_residual_bits = 0;
1011         unsigned i, partition_order;
1012         unsigned best_parameters_index = 0, parameters[2][1 << FLAC__MAX_RICE_PARTITION_ORDER];
1013         int32 r;
1014
1015         /* compute the abs(residual) for use later */
1016         for(i = 0; i < residual_samples; i++) {
1017                 r = residual[i];
1018                 abs_residual[i] = (uint32)(r<0? -r : r);
1019         }
1020
1021         for(partition_order = 0; partition_order <= max_partition_order; partition_order++) {
1022                 if(!encoder_set_partitioned_rice_(abs_residual, residual_samples, predictor_order, rice_parameter, partition_order, parameters[!best_parameters_index], &residual_bits)) {
1023                         assert(best_residual_bits != 0);
1024                         break;
1025                 }
1026                 if(best_residual_bits == 0 || residual_bits < best_residual_bits) {
1027                         best_residual_bits = residual_bits;
1028                         *best_partition_order = partition_order;
1029                         best_parameters_index = !best_parameters_index;
1030                 }
1031         }
1032         memcpy(best_parameters, parameters[best_parameters_index], sizeof(unsigned)*(1<<(*best_partition_order)));
1033
1034         return best_residual_bits;
1035 }
1036
1037 #ifdef ESTIMATE_RICE_BITS
1038 #undef ESTIMATE_RICE_BITS
1039 #endif
1040 #define ESTIMATE_RICE_BITS(value, parameter) ((value) >> (parameter))
1041
1042 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)
1043 {
1044         unsigned bits_ = FLAC__ENTROPY_CODING_METHOD_TYPE_LEN + FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_ORDER_LEN;
1045
1046         if(partition_order == 0) {
1047                 unsigned i;
1048 #ifdef ESTIMATE_RICE_BITS
1049                 const unsigned rice_parameter_estimate = rice_parameter-1;
1050                 bits_ += (1+rice_parameter) * residual_samples;
1051 #endif
1052                 parameters[0] = rice_parameter;
1053                 bits_ += FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN;
1054                 for(i = 0; i < residual_samples; i++)
1055 #ifdef ESTIMATE_RICE_BITS
1056                         bits_ += ESTIMATE_RICE_BITS(abs_residual[i], rice_parameter_estimate);
1057 #else
1058                         bits_ += FLAC__bitbuffer_rice_bits(residual[i], rice_parameter);
1059 #endif
1060         }
1061         else {
1062                 unsigned i, j, k = 0, k_last = 0;
1063                 unsigned mean, parameter, partition_samples;
1064                 const unsigned max_parameter = (1u << FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN) - 1;
1065                 for(i = 0; i < (1u<<partition_order); i++) {
1066                         partition_samples = (residual_samples+predictor_order) >> partition_order;
1067                         if(i == 0) {
1068                                 if(partition_samples <= predictor_order)
1069                                         return false;
1070                                 else
1071                                         partition_samples -= predictor_order;
1072                         }
1073                         mean = partition_samples >> 1;
1074                         for(j = 0; j < partition_samples; j++, k++)
1075                                 mean += abs_residual[k];
1076                         mean /= partition_samples;
1077                         /* calc parameter = floor(log2(mean)) + 1 */
1078                         parameter = 0;
1079                         while(mean) {
1080                                 parameter++;
1081                                 mean >>= 1;
1082                         }
1083                         if(parameter > max_parameter)
1084                                 parameter = max_parameter;
1085                         parameters[i] = parameter;
1086                         bits_ += FLAC__ENTROPY_CODING_METHOD_PARTITIONED_RICE_PARAMETER_LEN;
1087 #ifdef ESTIMATE_RICE_BITS
1088                         bits_ += (1+parameter) * partition_samples;
1089                         --parameter;
1090 #endif
1091                         for(j = k_last; j < k; j++)
1092 #ifdef ESTIMATE_RICE_BITS
1093                                 bits_ += ESTIMATE_RICE_BITS(abs_residual[j], parameter);
1094 #else
1095                                 bits_ += FLAC__bitbuffer_rice_bits(residual[j], parameter);
1096 #endif
1097                         k_last = k;
1098                 }
1099         }
1100
1101         *bits = bits_;
1102         return true;
1103 }