replaygain_synthesis.c : Replace an int64_t/int32_t operation with a shift.
authorErik de Castro Lopo <erikd@mega-nerd.com>
Sun, 18 May 2014 03:40:15 +0000 (13:40 +1000)
committerErik de Castro Lopo <erikd@mega-nerd.com>
Sun, 18 May 2014 03:49:56 +0000 (13:49 +1000)
Patch-from: lvqcl <lvqcl.mail@gmail.com>

src/share/replaygain_synthesis/replaygain_synthesis.c

index d65b412..b7fbfd3 100644 (file)
@@ -294,41 +294,6 @@ static FLAC__int64 dither_output_(DitherContext *d, FLAC__bool do_dithering, int
 
 size_t FLAC__replaygain_synthesis__apply_gain(FLAC__byte *data_out, FLAC__bool little_endian_data_out, FLAC__bool unsigned_data_out, const FLAC__int32 * const input[], unsigned wide_samples, unsigned channels, const unsigned source_bps, const unsigned target_bps, const double scale, const FLAC__bool hard_limit, FLAC__bool do_dithering, DitherContext *dither_context)
 {
-       static const FLAC__int32 conv_factors_[33] = {
-               -1, /* 0 bits-per-sample (not supported) */
-               -1, /* 1 bits-per-sample (not supported) */
-               -1, /* 2 bits-per-sample (not supported) */
-               -1, /* 3 bits-per-sample (not supported) */
-               268435456, /* 4 bits-per-sample */
-               134217728, /* 5 bits-per-sample */
-               67108864, /* 6 bits-per-sample */
-               33554432, /* 7 bits-per-sample */
-               16777216, /* 8 bits-per-sample */
-               8388608, /* 9 bits-per-sample */
-               4194304, /* 10 bits-per-sample */
-               2097152, /* 11 bits-per-sample */
-               1048576, /* 12 bits-per-sample */
-               524288, /* 13 bits-per-sample */
-               262144, /* 14 bits-per-sample */
-               131072, /* 15 bits-per-sample */
-               65536, /* 16 bits-per-sample */
-               32768, /* 17 bits-per-sample */
-               16384, /* 18 bits-per-sample */
-               8192, /* 19 bits-per-sample */
-               4096, /* 20 bits-per-sample */
-               2048, /* 21 bits-per-sample */
-               1024, /* 22 bits-per-sample */
-               512, /* 23 bits-per-sample */
-               256, /* 24 bits-per-sample */
-               128, /* 25 bits-per-sample */
-               64, /* 26 bits-per-sample */
-               32, /* 27 bits-per-sample */
-               16, /* 28 bits-per-sample */
-               8, /* 29 bits-per-sample */
-               4, /* 30 bits-per-sample */
-               2, /* 31 bits-per-sample */
-               1 /* 32 bits-per-sample */
-       };
        static const FLAC__int64 hard_clip_factors_[33] = {
                0, /* 0 bits-per-sample (not supported) */
                0, /* 1 bits-per-sample (not supported) */
@@ -364,7 +329,7 @@ size_t FLAC__replaygain_synthesis__apply_gain(FLAC__byte *data_out, FLAC__bool l
                -1073741824, /* 31 bits-per-sample */
                (FLAC__int64)(-1073741824) * 2 /* 32 bits-per-sample */
        };
-       const FLAC__int32 conv_factor = conv_factors_[target_bps];
+       const FLAC__int32 conv_shift = 32 - target_bps;
        const FLAC__int64 hard_clip_factor = hard_clip_factors_[target_bps];
        /*
         * The integer input coming in has a varying range based on the
@@ -409,7 +374,7 @@ size_t FLAC__replaygain_synthesis__apply_gain(FLAC__byte *data_out, FLAC__bool l
                        }
                        sample *= 2147483647.;
 
-                       val64 = dither_output_(dither_context, do_dithering, noise_shaping, (i + last_history_index) % 32, sample, channel) / conv_factor;
+                       val64 = dither_output_(dither_context, do_dithering, noise_shaping, (i + last_history_index) % 32, sample, channel) >> conv_shift;
 
                        val32 = (FLAC__int32)val64;
                        if(val64 >= -hard_clip_factor)