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use array for dynamic range scaling factors

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Originally committed as revision 9953 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2007-08-05 21:10:09 +00:00
parent 5abee3186c
commit 77416325cb
1 changed files with 10 additions and 15 deletions
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25
libavcodec/ac3dec.c
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@ -163,8 +163,7 @@ typedef struct {
float downmix_coeffs[AC3_MAX_CHANNELS][2]; ///< stereo downmix coefficients
float dialnorm[2]; ///< dialogue normalization
float dynrng; //dynamic range gain
float dynrng2; //dynamic range gain for 1+1 mode
float dynrng[2]; ///< dynamic range
float cplco[AC3_MAX_CHANNELS][18]; //coupling coordinates
int ncplbnd; //number of coupling bands
int ncplsubnd; //number of coupling sub bands
@ -782,19 +781,15 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
ctx->dither_all = 0;
}
if (get_bits1(gb)) { /* dynamic range */
ctx->dynrng = dynrng_tbl[get_bits(gb, 8)];
} else if(blk == 0) {
ctx->dynrng = 1.0;
}
if(acmod == AC3_ACMOD_DUALMONO) { /* dynamic range 1+1 mode */
/* dynamic range */
i = !(ctx->acmod);
do {
if(get_bits1(gb)) {
ctx->dynrng2 = dynrng_tbl[get_bits(gb, 8)];
ctx->dynrng[i] = dynrng_tbl[get_bits(gb, 8)];
} else if(blk == 0) {
ctx->dynrng2 = 1.0;
ctx->dynrng[i] = 1.0f;
}
}
} while(i--);
if (get_bits1(gb)) { /* coupling strategy */
memset(bit_alloc_stages, 3, AC3_MAX_CHANNELS);
@ -1022,10 +1017,10 @@ static int ac3_parse_audio_block(AC3DecodeContext *ctx, int blk)
/* apply scaling to coefficients (headroom, dialnorm, dynrng) */
for(ch=1; ch<=ctx->nchans; ch++) {
float gain = 2.0f * ctx->mul_bias;
if(ctx->acmod == AC3_ACMOD_DUALMONO && ch == 2) {
gain *= ctx->dialnorm[ch-1] * ctx->dynrng2;
if(ctx->acmod == AC3_ACMOD_DUALMONO) {
gain *= ctx->dialnorm[ch-1] * ctx->dynrng[ch-1];
} else {
gain *= ctx->dialnorm[0] * ctx->dynrng;
gain *= ctx->dialnorm[0] * ctx->dynrng[0];
}
for(i=0; i<ctx->endmant[ch]; i++) {
ctx->transform_coeffs[ch][i] *= gain;