[FFmpeg-cvslog] r9907 - trunk/libavcodec/ac3dec.c
jbr
subversion
Sat Aug 4 15:52:57 CEST 2007
Author: jbr
Date: Sat Aug 4 15:52:56 2007
New Revision: 9907
Log:
cosmetics: use more appropriate names for iterator variables.
Modified:
trunk/libavcodec/ac3dec.c
Modified: trunk/libavcodec/ac3dec.c
==============================================================================
--- trunk/libavcodec/ac3dec.c (original)
+++ trunk/libavcodec/ac3dec.c Sat Aug 4 15:52:56 2007
@@ -551,18 +551,18 @@ static void remove_dithering(AC3DecodeCo
*/
static int get_transform_coeffs(AC3DecodeContext * ctx)
{
- int i, end;
+ int ch, i, end;
int got_cplchan = 0;
mant_groups m;
m.b1ptr = m.b2ptr = m.b4ptr = 3;
- for (i = 0; i < ctx->nfchans; i++) {
+ for (ch = 0; ch < ctx->nfchans; ch++) {
/* transform coefficients for individual channel */
- if (get_transform_coeffs_ch(ctx, i, &m))
+ if (get_transform_coeffs_ch(ctx, ch, &m))
return -1;
/* tranform coefficients for coupling channels */
- if (ctx->chincpl[i]) {
+ if (ctx->chincpl[ch]) {
if (!got_cplchan) {
if (get_transform_coeffs_ch(ctx, -2, &m)) {
av_log(NULL, AV_LOG_ERROR, "error in decoupling channels\n");
@@ -573,10 +573,10 @@ static int get_transform_coeffs(AC3Decod
}
end = ctx->cplendmant;
} else {
- end = ctx->endmant[i];
+ end = ctx->endmant[ch];
}
do
- ctx->transform_coeffs[i + 1][end] = 0;
+ ctx->transform_coeffs[ch + 1][end] = 0;
while(++end < 256);
}
if (ctx->lfeon) {
@@ -701,13 +701,13 @@ static int ac3_parse_audio_block(AC3Deco
GetBitContext *gb = &ctx->gb;
int bit_alloc_flags = 0;
- for (i = 0; i < nfchans; i++) /*block switch flag */
- ctx->blksw[i] = get_bits1(gb);
+ for (ch = 0; ch < nfchans; ch++) /*block switch flag */
+ ctx->blksw[ch] = get_bits1(gb);
ctx->dither_all = 1;
- for (i = 0; i < nfchans; i++) { /* dithering flag */
- ctx->dithflag[i] = get_bits1(gb);
- if(!ctx->dithflag[i])
+ for (ch = 0; ch < nfchans; ch++) { /* dithering flag */
+ ctx->dithflag[ch] = get_bits1(gb);
+ if(!ctx->dithflag[ch])
ctx->dither_all = 0;
}
@@ -730,8 +730,8 @@ static int ac3_parse_audio_block(AC3Deco
if (ctx->cplinu) { /* coupling in use */
int cplbegf, cplendf;
- for (i = 0; i < nfchans; i++)
- ctx->chincpl[i] = get_bits1(gb);
+ for (ch = 0; ch < nfchans; ch++)
+ ctx->chincpl[ch] = get_bits1(gb);
if (acmod == AC3_ACMOD_STEREO)
ctx->phsflginu = get_bits1(gb); //phase flag in use
@@ -747,23 +747,23 @@ static int ac3_parse_audio_block(AC3Deco
ctx->ncplbnd = ctx->ncplsubnd = 3 + cplendf - cplbegf;
ctx->cplstrtmant = cplbegf * 12 + 37;
ctx->cplendmant = cplendf * 12 + 73;
- for (i = 0; i < ctx->ncplsubnd - 1; i++) { /* coupling band structure */
+ for (bnd = 0; bnd < ctx->ncplsubnd - 1; bnd++) { /* coupling band structure */
if (get_bits1(gb)) {
- ctx->cplbndstrc[i] = 1;
+ ctx->cplbndstrc[bnd] = 1;
ctx->ncplbnd--;
}
}
} else {
- for (i = 0; i < nfchans; i++)
- ctx->chincpl[i] = 0;
+ for (ch = 0; ch < nfchans; ch++)
+ ctx->chincpl[ch] = 0;
}
}
if (ctx->cplinu) {
int cplcoe = 0;
- for (i = 0; i < nfchans; i++) {
- if (ctx->chincpl[i]) {
+ for (ch = 0; ch < nfchans; ch++) {
+ if (ctx->chincpl[ch]) {
if (get_bits1(gb)) { /* coupling co-ordinates */
int mstrcplco, cplcoexp, cplcomant;
cplcoe = 1;
@@ -772,10 +772,10 @@ static int ac3_parse_audio_block(AC3Deco
cplcoexp = get_bits(gb, 4);
cplcomant = get_bits(gb, 4);
if (cplcoexp == 15)
- ctx->cplco[i][bnd] = cplcomant / 16.0f;
+ ctx->cplco[ch][bnd] = cplcomant / 16.0f;
else
- ctx->cplco[i][bnd] = (cplcomant + 16.0f) / 32.0f;
- ctx->cplco[i][bnd] *= scale_factors[cplcoexp + mstrcplco];
+ ctx->cplco[ch][bnd] = (cplcomant + 16.0f) / 32.0f;
+ ctx->cplco[ch][bnd] *= scale_factors[cplcoexp + mstrcplco];
}
}
}
@@ -804,22 +804,22 @@ static int ac3_parse_audio_block(AC3Deco
ctx->lfeexpstr = EXP_REUSE;
if (ctx->cplinu) /* coupling exponent strategy */
ctx->cplexpstr = get_bits(gb, 2);
- for (i = 0; i < nfchans; i++) /* channel exponent strategy */
- ctx->chexpstr[i] = get_bits(gb, 2);
+ for (ch = 0; ch < nfchans; ch++) /* channel exponent strategy */
+ ctx->chexpstr[ch] = get_bits(gb, 2);
if (ctx->lfeon) /* lfe exponent strategy */
ctx->lfeexpstr = get_bits1(gb);
- for (i = 0; i < nfchans; i++) { /* channel bandwidth code */
- if (ctx->chexpstr[i] != EXP_REUSE) {
- if (ctx->chincpl[i])
- ctx->endmant[i] = ctx->cplstrtmant;
+ for (ch = 0; ch < nfchans; ch++) { /* channel bandwidth code */
+ if (ctx->chexpstr[ch] != EXP_REUSE) {
+ if (ctx->chincpl[ch])
+ ctx->endmant[ch] = ctx->cplstrtmant;
else {
int chbwcod = get_bits(gb, 6);
if (chbwcod > 60) {
av_log(NULL, AV_LOG_ERROR, "chbwcod = %d > 60", chbwcod);
return -1;
}
- ctx->endmant[i] = chbwcod * 3 + 73;
+ ctx->endmant[ch] = chbwcod * 3 + 73;
}
}
}
@@ -833,14 +833,14 @@ static int ac3_parse_audio_block(AC3Deco
decode_exponents(gb, ctx->cplexpstr, ngrps, absexp, &ctx->dcplexps[ctx->cplstrtmant]);
}
- for (i = 0; i < nfchans; i++) { /* fbw channel exponents */
- if (ctx->chexpstr[i] != EXP_REUSE) {
+ for (ch = 0; ch < nfchans; ch++) { /* fbw channel exponents */
+ if (ctx->chexpstr[ch] != EXP_REUSE) {
int grpsize, ngrps, absexp;
- bit_alloc_flags |= 1 << i;
- grpsize = 3 << (ctx->chexpstr[i] - 1);
- ngrps = (ctx->endmant[i] + grpsize - 4) / grpsize;
- absexp = ctx->dexps[i][0] = get_bits(gb, 4);
- decode_exponents(gb, ctx->chexpstr[i], ngrps, absexp, &ctx->dexps[i][1]);
+ bit_alloc_flags |= 1 << ch;
+ grpsize = 3 << (ctx->chexpstr[ch] - 1);
+ ngrps = (ctx->endmant[ch] + grpsize - 4) / grpsize;
+ absexp = ctx->dexps[ch][0] = get_bits(gb, 4);
+ decode_exponents(gb, ctx->chexpstr[ch], ngrps, absexp, &ctx->dexps[ch][1]);
skip_bits(gb, 2); /* skip gainrng */
}
}
@@ -870,9 +870,9 @@ static int ac3_parse_audio_block(AC3Deco
ctx->cplsnroffst = (csnr + get_bits(gb, 4)) << 2;
ctx->cplfgain = ff_fgaintab[get_bits(gb, 3)];
}
- for (i = 0; i < nfchans; i++) { /* channel fine snr offset and fast gain code */
- ctx->snroffst[i] = (csnr + get_bits(gb, 4)) << 2;
- ctx->fgain[i] = ff_fgaintab[get_bits(gb, 3)];
+ for (ch = 0; ch < nfchans; ch++) { /* channel fine snr offset and fast gain code */
+ ctx->snroffst[ch] = (csnr + get_bits(gb, 4)) << 2;
+ ctx->fgain[ch] = ff_fgaintab[get_bits(gb, 3)];
}
if (ctx->lfeon) { /* lfe fine snr offset and fast gain code */
ctx->lfesnroffst = (csnr + get_bits(gb, 4)) << 2;
@@ -897,9 +897,9 @@ static int ac3_parse_audio_block(AC3Deco
}
}
- for (i = 0; i < nfchans; i++) {
- ctx->deltbae[i] = get_bits(gb, 2);
- if (ctx->deltbae[i] == DBA_RESERVED) {
+ for (ch = 0; ch < nfchans; ch++) {
+ ctx->deltbae[ch] = get_bits(gb, 2);
+ if (ctx->deltbae[ch] == DBA_RESERVED) {
av_log(NULL, AV_LOG_ERROR, "delta bit allocation strategy reserved\n");
return -1;
}
@@ -916,21 +916,21 @@ static int ac3_parse_audio_block(AC3Deco
}
}
- for (i = 0; i < nfchans; i++) {
- if (ctx->deltbae[i] == DBA_NEW) {/*channel delta offset, len and bit allocation */
- ctx->deltnseg[i] = get_bits(gb, 3);
- for (seg = 0; seg <= ctx->deltnseg[i]; seg++) {
- ctx->deltoffst[i][seg] = get_bits(gb, 5);
- ctx->deltlen[i][seg] = get_bits(gb, 4);
- ctx->deltba[i][seg] = get_bits(gb, 3);
+ for (ch = 0; ch < nfchans; ch++) {
+ if (ctx->deltbae[ch] == DBA_NEW) {/*channel delta offset, len and bit allocation */
+ ctx->deltnseg[ch] = get_bits(gb, 3);
+ for (seg = 0; seg <= ctx->deltnseg[ch]; seg++) {
+ ctx->deltoffst[ch][seg] = get_bits(gb, 5);
+ ctx->deltlen[ch][seg] = get_bits(gb, 4);
+ ctx->deltba[ch][seg] = get_bits(gb, 3);
}
}
}
} else if(blk == 0) {
if(ctx->cplinu)
ctx->cpldeltbae = DBA_NONE;
- for(i=0; i<nfchans; i++) {
- ctx->deltbae[i] = DBA_NONE;
+ for(ch=0; ch<nfchans; ch++) {
+ ctx->deltbae[ch] = DBA_NONE;
}
}
@@ -944,14 +944,14 @@ static int ac3_parse_audio_block(AC3Deco
ctx->cpldeltoffst, ctx->cpldeltlen,
ctx->cpldeltba);
}
- for (i = 0; i < nfchans; i++) {
- if ((bit_alloc_flags >> i) & 1) {
+ for (ch = 0; ch < nfchans; ch++) {
+ if ((bit_alloc_flags >> ch) & 1) {
ac3_parametric_bit_allocation(&ctx->bit_alloc_params,
- ctx->bap[i], ctx->dexps[i], 0,
- ctx->endmant[i], ctx->snroffst[i],
- ctx->fgain[i], 0, ctx->deltbae[i],
- ctx->deltnseg[i], ctx->deltoffst[i],
- ctx->deltlen[i], ctx->deltba[i]);
+ ctx->bap[ch], ctx->dexps[ch], 0,
+ ctx->endmant[ch], ctx->snroffst[ch],
+ ctx->fgain[ch], 0, ctx->deltbae[ch],
+ ctx->deltnseg[ch], ctx->deltoffst[ch],
+ ctx->deltlen[ch], ctx->deltba[ch]);
}
}
if (ctx->lfeon && (bit_alloc_flags & 32)) {
@@ -1024,11 +1024,11 @@ static int ac3_decode_frame(AVCodecConte
{
AC3DecodeContext *ctx = (AC3DecodeContext *)avctx->priv_data;
int16_t *out_samples = (int16_t *)data;
- int i, j, k, start;
+ int i, blk, ch, start;
int32_t *int_ptr[6];
- for (i = 0; i < 6; i++)
- int_ptr[i] = (int32_t *)(&ctx->output[i]);
+ for (ch = 0; ch < 6; ch++)
+ int_ptr[ch] = (int32_t *)(&ctx->output[ch]);
//Initialize the GetBitContext with the start of valid AC3 Frame.
init_get_bits(&ctx->gb, buf, buf_size * 8);
@@ -1056,16 +1056,16 @@ static int ac3_decode_frame(AVCodecConte
//av_log(avctx, AV_LOG_INFO, "channels = %d \t bit rate = %d \t sampling rate = %d \n", avctx->channels, avctx->bit_rate * 1000, avctx->sample_rate);
//Parse the Audio Blocks.
- for (i = 0; i < NB_BLOCKS; i++) {
- if (ac3_parse_audio_block(ctx, i)) {
+ for (blk = 0; blk < NB_BLOCKS; blk++) {
+ if (ac3_parse_audio_block(ctx, blk)) {
av_log(avctx, AV_LOG_ERROR, "error parsing the audio block\n");
*data_size = 0;
return ctx->frame_size;
}
start = (ctx->output_mode & AC3_OUTPUT_LFEON) ? 0 : 1;
- for (k = 0; k < 256; k++)
- for (j = start; j <= ctx->nfchans; j++)
- *(out_samples++) = convert(int_ptr[j][k]);
+ for (i = 0; i < 256; i++)
+ for (ch = start; ch <= ctx->nfchans; ch++)
+ *(out_samples++) = convert(int_ptr[ch][i]);
}
*data_size = NB_BLOCKS * 256 * avctx->channels * sizeof (int16_t);
return ctx->frame_size;
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