Revision cb6247cb
| libavcodec/ac3enc.c | ||
|---|---|---|
| 929 | 929 |
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| 930 | 930 |
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| 931 | 931 |
/** |
| 932 |
* Perform bit allocation search. |
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| 933 |
* Finds the SNR offset value that maximizes quality and fits in the specified |
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| 934 |
* frame size. Output is the SNR offset and a set of bit allocation pointers |
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| 935 |
* used to quantize the mantissas. |
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| 932 |
* Constant bitrate bit allocation search. |
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| 933 |
* Find the largest SNR offset that will allow data to fit in the frame. |
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| 936 | 934 |
*/ |
| 937 |
static int compute_bit_allocation(AC3EncodeContext *s)
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static int cbr_bit_allocation(AC3EncodeContext *s)
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{
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int ch; |
| 940 | 938 |
int bits_left; |
| 941 | 939 |
int snr_offset; |
| 942 | 940 |
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/* count frame bits other than exponents and mantissas */ |
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count_frame_bits(s); |
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| 945 |
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/* calculate psd and masking curve before doing bit allocation */ |
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bit_alloc_masking(s); |
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| 948 |
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/* now the big work begins : do the bit allocation. Modify the snr |
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offset until we can pack everything in the requested frame size */ |
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bits_left = 8 * s->frame_size - (s->frame_bits + s->exponent_bits); |
| 953 | 942 |
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| 954 | 943 |
snr_offset = s->coarse_snr_offset << 4; |
| ... | ... | |
| 991 | 980 |
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| 992 | 981 |
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| 993 | 982 |
/** |
| 983 |
* Perform bit allocation search. |
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| 984 |
* Finds the SNR offset value that maximizes quality and fits in the specified |
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| 985 |
* frame size. Output is the SNR offset and a set of bit allocation pointers |
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| 986 |
* used to quantize the mantissas. |
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| 987 |
*/ |
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static int compute_bit_allocation(AC3EncodeContext *s) |
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{
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/* count frame bits other than exponents and mantissas */ |
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count_frame_bits(s); |
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| 992 |
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/* calculate psd and masking curve before doing bit allocation */ |
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bit_alloc_masking(s); |
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| 995 |
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return cbr_bit_allocation(s); |
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} |
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| 998 |
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| 999 |
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| 1000 |
/** |
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| 994 | 1001 |
* Symmetric quantization on 'levels' levels. |
| 995 | 1002 |
*/ |
| 996 | 1003 |
static inline int sym_quant(int c, int e, int levels) |
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