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Separate functionally different calculations in ac3_encode_frame().

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Originally committed as revision 25988 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles
2010-12-14 14:52:53 +00:00
parent 98f6ee4453
commit 152cc52803
1 changed files with 13 additions and 2 deletions
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15
libavcodec/ac3enc.c
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@@ -1114,9 +1114,8 @@ static int ac3_encode_frame(AVCodecContext *avctx,
AC3_BLOCK_SIZE * sizeof(planar_samples[0][0])); AC3_BLOCK_SIZE * sizeof(planar_samples[0][0]));
} }
frame_bits = 0; /* apply MDCT */
for (ch = 0; ch < s->channels; ch++) { for (ch = 0; ch < s->channels; ch++) {
/* fixed mdct to the six sub blocks & exponent computation */
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) { for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
int16_t *input_samples = &planar_samples[ch][blk * AC3_BLOCK_SIZE]; int16_t *input_samples = &planar_samples[ch][blk * AC3_BLOCK_SIZE];
@@ -1137,7 +1136,12 @@ static int ac3_encode_frame(AVCodecContext *avctx,
/* do the MDCT */ /* do the MDCT */
mdct512(mdct_coef[blk][ch], windowed_samples); mdct512(mdct_coef[blk][ch], windowed_samples);
}
}
/* extract exponents */
for (ch = 0; ch < s->channels; ch++) {
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
/* compute "exponents". We take into account the normalization there */ /* compute "exponents". We take into account the normalization there */
for (i = 0; i < AC3_MAX_COEFS; i++) { for (i = 0; i < AC3_MAX_COEFS; i++) {
int e; int e;
@@ -1154,9 +1158,16 @@ static int ac3_encode_frame(AVCodecContext *avctx,
exp[blk][ch][i] = e; exp[blk][ch][i] = e;
} }
} }
}
/* compute exponent strategies */
for (ch = 0; ch < s->channels; ch++) {
compute_exp_strategy_ch(exp_strategy, exp, ch, ch == s->lfe_channel); compute_exp_strategy_ch(exp_strategy, exp, ch, ch == s->lfe_channel);
}
/* encode exponents */
frame_bits = 0;
for (ch = 0; ch < s->channels; ch++) {
/* compute the exponents as the decoder will see them. The /* compute the exponents as the decoder will see them. The
EXP_REUSE case must be handled carefully : we select the EXP_REUSE case must be handled carefully : we select the
min of the exponents */ min of the exponents */