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Split frame size adjustment into a separate function.

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Originally committed as revision 25992 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2010-12-14 14:53:06 +00:00
parent dfdf73eb1a
commit 160d85f5b0
1 changed files with 19 additions and 9 deletions
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28
libavcodec/ac3enc.c
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@ -105,6 +105,22 @@ static int16_t xcos1[128];
static int16_t xsin1[128];
/**
* Adjust the frame size to make the average bit rate match the target bit rate.
* This is only needed for 11025, 22050, and 44100 sample rates.
*/
static void adjust_frame_size(AC3EncodeContext *s)
{
while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
s->bits_written -= s->bit_rate;
s->samples_written -= s->sample_rate;
}
s->frame_size = s->frame_size_min + 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
s->bits_written += s->frame_size * 8;
s->samples_written += AC3_FRAME_SIZE;
}
/**
* Deinterleave input samples.
* Channels are reordered from FFmpeg's default order to AC-3 order.
@ -1296,21 +1312,15 @@ static int ac3_encode_frame(AVCodecContext *avctx,
int8_t exp_shift[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS];
int frame_bits;
if (s->bit_alloc.sr_code == 1)
adjust_frame_size(s);
deinterleave_input_samples(s, samples, planar_samples);
apply_mdct(s, planar_samples, exp_shift, mdct_coef);
frame_bits = process_exponents(s, mdct_coef, exp_shift, exp, exp_strategy, encoded_exp);
/* adjust for fractional frame sizes */
while (s->bits_written >= s->bit_rate && s->samples_written >= s->sample_rate) {
s->bits_written -= s->bit_rate;
s->samples_written -= s->sample_rate;
}
s->frame_size = s->frame_size_min + 2 * (s->bits_written * s->sample_rate < s->samples_written * s->bit_rate);
s->bits_written += s->frame_size * 8;
s->samples_written += AC3_FRAME_SIZE;
compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits);
/* everything is known... let's output the frame */
output_frame_header(s, frame);