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@ -93,6 +93,8 @@ typedef struct AC3EncodeContext { |
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int coarse_snr_offset; ///< coarse SNR offsets (csnroffst)
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int fast_gain_code[AC3_MAX_CHANNELS]; ///< fast gain codes (signal-to-mask ratio) (fgaincod)
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int fine_snr_offset[AC3_MAX_CHANNELS]; ///< fine SNR offsets (fsnroffst)
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int frame_bits; ///< all frame bits except exponents and mantissas
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int exponent_bits; ///< number of bits used for exponents
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/* mantissa encoding */ |
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int mant1_cnt, mant2_cnt, mant4_cnt; ///< mantissa counts for bap=1,2,4
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@ -663,9 +665,8 @@ static void encode_exponents(AC3EncodeContext *s, |
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* Group exponents. |
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* 3 delta-encoded exponents are in each 7-bit group. The number of groups |
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* varies depending on exponent strategy and bandwidth. |
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* @return bits needed to encode the exponents |
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*/ |
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static int group_exponents(AC3EncodeContext *s, |
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static void group_exponents(AC3EncodeContext *s, |
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uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS], |
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uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS], |
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uint8_t num_exp_groups[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS], |
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@ -715,7 +716,7 @@ static int group_exponents(AC3EncodeContext *s, |
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} |
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} |
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return bit_count; |
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s->exponent_bits = bit_count; |
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} |
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@ -723,9 +724,8 @@ static int group_exponents(AC3EncodeContext *s, |
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* Calculate final exponents from the supplied MDCT coefficients and exponent shift. |
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* Extract exponents from MDCT coefficients, calculate exponent strategies, |
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* and encode final exponents. |
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* @return bits needed to encode the exponents |
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*/ |
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static int process_exponents(AC3EncodeContext *s, |
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static void process_exponents(AC3EncodeContext *s, |
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int32_t mdct_coef[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS], |
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int8_t exp_shift[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS], |
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uint8_t exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS], |
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@ -740,7 +740,7 @@ static int process_exponents(AC3EncodeContext *s, |
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encode_exponents(s, exp, exp_strategy, num_exp_groups, encoded_exp); |
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return group_exponents(s, encoded_exp, exp_strategy, num_exp_groups, grouped_exp); |
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group_exponents(s, encoded_exp, exp_strategy, num_exp_groups, grouped_exp); |
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} |
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@ -777,9 +777,8 @@ static void bit_alloc_init(AC3EncodeContext *s) |
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/**
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* Count the bits used to encode the frame, minus exponents and mantissas. |
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* @return bit count |
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*/ |
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static int count_frame_bits(AC3EncodeContext *s, |
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static void count_frame_bits(AC3EncodeContext *s, |
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uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]) |
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{ |
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static const int frame_bits_inc[8] = { 0, 0, 2, 2, 2, 4, 2, 4 }; |
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@ -822,7 +821,7 @@ static int count_frame_bits(AC3EncodeContext *s, |
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/* CRC */ |
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frame_bits += 16; |
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return frame_bits; |
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s->frame_bits = frame_bits; |
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} |
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@ -958,17 +957,17 @@ static int bit_alloc(AC3EncodeContext *s, |
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static int compute_bit_allocation(AC3EncodeContext *s, |
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uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS], |
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uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS], |
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uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS], |
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int frame_bits) |
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uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]) |
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{ |
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int ch; |
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int frame_bits; |
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int coarse_snr_offset, fine_snr_offset; |
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uint8_t bap1[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS]; |
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int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS]; |
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int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS]; |
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/* count frame bits other than exponents and mantissas */ |
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frame_bits += count_frame_bits(s, exp_strategy); |
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count_frame_bits(s, exp_strategy); |
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/* calculate psd and masking curve before doing bit allocation */ |
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bit_alloc_masking(s, encoded_exp, exp_strategy, psd, mask); |
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@ -976,6 +975,7 @@ static int compute_bit_allocation(AC3EncodeContext *s, |
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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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frame_bits = s->frame_bits + s->exponent_bits; |
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coarse_snr_offset = s->coarse_snr_offset; |
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while (coarse_snr_offset >= 0 && |
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bit_alloc(s, mask, psd, bap, frame_bits, coarse_snr_offset, 0) < 0) |
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@ -1442,7 +1442,6 @@ static int ac3_encode_frame(AVCodecContext *avctx, |
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uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS]; |
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int8_t exp_shift[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS]; |
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uint16_t qmant[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS]; |
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int frame_bits; |
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int ret; |
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if (s->bit_alloc.sr_code == 1) |
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@ -1452,10 +1451,10 @@ static int ac3_encode_frame(AVCodecContext *avctx, |
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apply_mdct(s, planar_samples, exp_shift, mdct_coef); |
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frame_bits = process_exponents(s, mdct_coef, exp_shift, exp, exp_strategy, |
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process_exponents(s, mdct_coef, exp_shift, exp, exp_strategy, |
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encoded_exp, num_exp_groups, grouped_exp); |
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ret = compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits); |
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ret = compute_bit_allocation(s, bap, encoded_exp, exp_strategy); |
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if (ret) { |
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av_log(avctx, AV_LOG_ERROR, "Bit allocation failed. Try increasing the bitrate.\n"); |
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return ret; |
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