virtualenv/FFmpeg
1
0
Fork 0
mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-01-08 13:22:53 +02:00
Code Issues Releases Activity

alacdec: cosmetics: rename 'wasted_bits' to 'extra_bits'.

Browse Source 
The bits are not wasted, they are additional low bits that are added to the
16-bit decompressed samples to increase the output sample depth.
This commit is contained in:
Justin Ruggles 2011-10-09 13:00:39 -04:00
parent dbbb9262ca
commit d251c85dce
1 changed files with 20 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

40
libavcodec/alac.c
View File

@ -72,7 +72,7 @@ typedef struct {
int32_t *outputsamples_buffer[MAX_CHANNELS]; int32_t *outputsamples_buffer[MAX_CHANNELS];
int32_t *wasted_bits_buffer[MAX_CHANNELS]; int32_t *extra_bits_buffer[MAX_CHANNELS];
/* stuff from setinfo */ /* stuff from setinfo */
uint32_t setinfo_max_samples_per_frame; /* 0x1000 = 4096 */ /* max samples per frame? */ uint32_t setinfo_max_samples_per_frame; /* 0x1000 = 4096 */ /* max samples per frame? */
@ -82,7 +82,7 @@ typedef struct {
uint8_t setinfo_rice_kmodifier; /* 0x0e */ uint8_t setinfo_rice_kmodifier; /* 0x0e */
/* end setinfo stuff */ /* end setinfo stuff */
int wasted_bits; int extra_bits; /**< number of extra bits beyond 16-bit */
} ALACContext; } ALACContext;
static inline int decode_scalar(GetBitContext *gb, int k, int limit, int readsamplesize){ static inline int decode_scalar(GetBitContext *gb, int k, int limit, int readsamplesize){
@ -338,8 +338,8 @@ static void reconstruct_stereo_16(int32_t *buffer[MAX_CHANNELS],
static void decorrelate_stereo_24(int32_t *buffer[MAX_CHANNELS], static void decorrelate_stereo_24(int32_t *buffer[MAX_CHANNELS],
int32_t *buffer_out, int32_t *buffer_out,
int32_t *wasted_bits_buffer[MAX_CHANNELS], int32_t *extra_bits_buffer[MAX_CHANNELS],
int wasted_bits, int extra_bits,
int numchannels, int numsamples, int numchannels, int numsamples,
uint8_t interlacing_shift, uint8_t interlacing_shift,
uint8_t interlacing_leftweight) uint8_t interlacing_leftweight)
@ -357,9 +357,9 @@ static void decorrelate_stereo_24(int32_t *buffer[MAX_CHANNELS],
a -= (b * interlacing_leftweight) >> interlacing_shift; a -= (b * interlacing_leftweight) >> interlacing_shift;
b += a; b += a;
if (wasted_bits) { if (extra_bits) {
b = (b << wasted_bits) | wasted_bits_buffer[0][i]; b = (b << extra_bits) | extra_bits_buffer[0][i];
a = (a << wasted_bits) | wasted_bits_buffer[1][i]; a = (a << extra_bits) | extra_bits_buffer[1][i];
} }
buffer_out[i * numchannels] = b << 8; buffer_out[i * numchannels] = b << 8;
@ -372,9 +372,9 @@ static void decorrelate_stereo_24(int32_t *buffer[MAX_CHANNELS],
left = buffer[0][i]; left = buffer[0][i];
right = buffer[1][i]; right = buffer[1][i];
if (wasted_bits) { if (extra_bits) {
left = (left << wasted_bits) | wasted_bits_buffer[0][i]; left = (left << extra_bits) | extra_bits_buffer[0][i];
right = (right << wasted_bits) | wasted_bits_buffer[1][i]; right = (right << extra_bits) | extra_bits_buffer[1][i];
} }
buffer_out[i * numchannels] = left << 8; buffer_out[i * numchannels] = left << 8;
@ -421,7 +421,7 @@ static int alac_decode_frame(AVCodecContext *avctx,
/* the output sample size is stored soon */ /* the output sample size is stored soon */
hassize = get_bits1(&alac->gb); hassize = get_bits1(&alac->gb);
alac->wasted_bits = get_bits(&alac->gb, 2) << 3; alac->extra_bits = get_bits(&alac->gb, 2) << 3;
/* whether the frame is compressed */ /* whether the frame is compressed */
isnotcompressed = get_bits1(&alac->gb); isnotcompressed = get_bits1(&alac->gb);
@ -444,7 +444,7 @@ static int alac_decode_frame(AVCodecContext *avctx,
} }
*outputsize = outputsamples * alac->bytespersample; *outputsize = outputsamples * alac->bytespersample;
readsamplesize = alac->setinfo_sample_size - (alac->wasted_bits) + channels - 1; readsamplesize = alac->setinfo_sample_size - alac->extra_bits + channels - 1;
if (readsamplesize > MIN_CACHE_BITS) { if (readsamplesize > MIN_CACHE_BITS) {
av_log(avctx, AV_LOG_ERROR, "readsamplesize too big (%d)\n", readsamplesize); av_log(avctx, AV_LOG_ERROR, "readsamplesize too big (%d)\n", readsamplesize);
return -1; return -1;
@ -474,11 +474,11 @@ static int alac_decode_frame(AVCodecContext *avctx,
predictor_coef_table[chan][i] = (int16_t)get_bits(&alac->gb, 16); predictor_coef_table[chan][i] = (int16_t)get_bits(&alac->gb, 16);
} }
if (alac->wasted_bits) { if (alac->extra_bits) {
int i, ch; int i, ch;
for (i = 0; i < outputsamples; i++) { for (i = 0; i < outputsamples; i++) {
for (ch = 0; ch < channels; ch++) for (ch = 0; ch < channels; ch++)
alac->wasted_bits_buffer[ch][i] = get_bits(&alac->gb, alac->wasted_bits); alac->extra_bits_buffer[ch][i] = get_bits(&alac->gb, alac->extra_bits);
} }
} }
for (chan = 0; chan < channels; chan++) { for (chan = 0; chan < channels; chan++) {
@ -532,7 +532,7 @@ static int alac_decode_frame(AVCodecContext *avctx,
} }
} }
} }
alac->wasted_bits = 0; alac->extra_bits = 0;
interlacing_shift = 0; interlacing_shift = 0;
interlacing_leftweight = 0; interlacing_leftweight = 0;
} }
@ -559,8 +559,8 @@ static int alac_decode_frame(AVCodecContext *avctx,
if (channels == 2) { if (channels == 2) {
decorrelate_stereo_24(alac->outputsamples_buffer, decorrelate_stereo_24(alac->outputsamples_buffer,
outbuffer, outbuffer,
alac->wasted_bits_buffer, alac->extra_bits_buffer,
alac->wasted_bits, alac->extra_bits,
alac->numchannels, alac->numchannels,
outputsamples, outputsamples,
interlacing_shift, interlacing_shift,
@ -587,7 +587,7 @@ static av_cold int alac_decode_close(AVCodecContext *avctx)
for (chan = 0; chan < alac->numchannels; chan++) { for (chan = 0; chan < alac->numchannels; chan++) {
av_freep(&alac->predicterror_buffer[chan]); av_freep(&alac->predicterror_buffer[chan]);
av_freep(&alac->outputsamples_buffer[chan]); av_freep(&alac->outputsamples_buffer[chan]);
av_freep(&alac->wasted_bits_buffer[chan]); av_freep(&alac->extra_bits_buffer[chan]);
} }
return 0; return 0;
@ -603,11 +603,11 @@ static int allocate_buffers(ALACContext *alac)
alac->outputsamples_buffer[chan] = alac->outputsamples_buffer[chan] =
av_malloc(alac->setinfo_max_samples_per_frame * 4); av_malloc(alac->setinfo_max_samples_per_frame * 4);
alac->wasted_bits_buffer[chan] = av_malloc(alac->setinfo_max_samples_per_frame * 4); alac->extra_bits_buffer[chan] = av_malloc(alac->setinfo_max_samples_per_frame * 4);
if (!alac->predicterror_buffer[chan] || if (!alac->predicterror_buffer[chan] ||
!alac->outputsamples_buffer[chan] || !alac->outputsamples_buffer[chan] ||
!alac->wasted_bits_buffer[chan]) { !alac->extra_bits_buffer[chan]) {
alac_decode_close(alac->avctx); alac_decode_close(alac->avctx);
return AVERROR(ENOMEM); return AVERROR(ENOMEM);
} }