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Split bit allocation search into a separate function.

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Originally committed as revision 26017 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles 2010-12-15 17:28:38 +00:00
parent a4a3bade0a
commit cb6247cb30
1 changed files with 21 additions and 14 deletions
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35
libavcodec/ac3enc.c
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@ -929,26 +929,15 @@ static int bit_alloc(AC3EncodeContext *s,
/** /**
* Perform bit allocation search. * Constant bitrate bit allocation search.
* Finds the SNR offset value that maximizes quality and fits in the specified * Find the largest SNR offset that will allow data to fit in the frame.
* frame size. Output is the SNR offset and a set of bit allocation pointers
* used to quantize the mantissas.
*/ */
static int compute_bit_allocation(AC3EncodeContext *s) static int cbr_bit_allocation(AC3EncodeContext *s)
{ {
int ch; int ch;
int bits_left; int bits_left;
int snr_offset; int snr_offset;
/* count frame bits other than exponents and mantissas */
count_frame_bits(s);
/* calculate psd and masking curve before doing bit allocation */
bit_alloc_masking(s);
/* now the big work begins : do the bit allocation. Modify the snr
offset until we can pack everything in the requested frame size */
bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits); bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits);
snr_offset = s->coarse_snr_offset << 4; snr_offset = s->coarse_snr_offset << 4;
@ -990,6 +979,24 @@ static int compute_bit_allocation(AC3EncodeContext *s)
} }
/**
* Perform bit allocation search.
* Finds the SNR offset value that maximizes quality and fits in the specified
* frame size. Output is the SNR offset and a set of bit allocation pointers
* used to quantize the mantissas.
*/
static int compute_bit_allocation(AC3EncodeContext *s)
{
/* count frame bits other than exponents and mantissas */
count_frame_bits(s);
/* calculate psd and masking curve before doing bit allocation */
bit_alloc_masking(s);
return cbr_bit_allocation(s);
}
/** /**
* Symmetric quantization on 'levels' levels. * Symmetric quantization on 'levels' levels.
*/ */