mirror of https://git.videolan.org/git/ffmpeg.git
Split out mantissa quantization into separate functions.
Originally committed as revision 25997 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Justin Ruggles
parent
5b44ede0ba
commit
b6a1e5236e
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@ -93,6 +93,7 @@ typedef struct AC3EncodeContext {
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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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uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr; ///< mantissa pointers for bap=1,2,4
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int16_t last_samples[AC3_MAX_CHANNELS][AC3_BLOCK_SIZE]; ///< last 256 samples from previous frame
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} AC3EncodeContext;
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@ -967,6 +968,127 @@ static inline int asym_quant(int c, int e, int qbits)
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}
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/**
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* Quantize a set of mantissas for a single channel in a single block.
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*/
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static void quantize_mantissas_blk_ch(AC3EncodeContext *s,
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int32_t *mdct_coef, int8_t exp_shift,
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uint8_t *encoded_exp, uint8_t *bap,
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uint16_t *qmant, int n)
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{
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int i;
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for (i = 0; i < n; i++) {
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int v;
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int c = mdct_coef[i];
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int e = encoded_exp[i] - exp_shift;
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int b = bap[i];
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switch (b) {
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case 0:
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v = 0;
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break;
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case 1:
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v = sym_quant(c, e, 3);
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switch (s->mant1_cnt) {
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case 0:
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s->qmant1_ptr = &qmant[i];
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v = 9 * v;
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s->mant1_cnt = 1;
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break;
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case 1:
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*s->qmant1_ptr += 3 * v;
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s->mant1_cnt = 2;
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v = 128;
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break;
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default:
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*s->qmant1_ptr += v;
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s->mant1_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 2:
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v = sym_quant(c, e, 5);
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switch (s->mant2_cnt) {
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case 0:
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s->qmant2_ptr = &qmant[i];
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v = 25 * v;
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s->mant2_cnt = 1;
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break;
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case 1:
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*s->qmant2_ptr += 5 * v;
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s->mant2_cnt = 2;
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v = 128;
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break;
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default:
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*s->qmant2_ptr += v;
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s->mant2_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 3:
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v = sym_quant(c, e, 7);
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break;
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case 4:
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v = sym_quant(c, e, 11);
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switch (s->mant4_cnt) {
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case 0:
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s->qmant4_ptr = &qmant[i];
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v = 11 * v;
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s->mant4_cnt = 1;
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break;
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default:
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*s->qmant4_ptr += v;
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s->mant4_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 5:
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v = sym_quant(c, e, 15);
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break;
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case 14:
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v = asym_quant(c, e, 14);
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break;
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case 15:
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v = asym_quant(c, e, 16);
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break;
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default:
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v = asym_quant(c, e, b - 1);
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break;
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}
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qmant[i] = v;
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}
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}
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/**
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* Quantize mantissas using coefficients, exponents, and bit allocation pointers.
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*/
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static void quantize_mantissas(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 encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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uint16_t qmant[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS])
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{
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int blk, ch;
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
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s->mant1_cnt = s->mant2_cnt = s->mant4_cnt = 0;
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s->qmant1_ptr = s->qmant2_ptr = s->qmant4_ptr = NULL;
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for (ch = 0; ch < s->channels; ch++) {
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quantize_mantissas_blk_ch(s, mdct_coef[blk][ch], exp_shift[blk][ch],
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encoded_exp[blk][ch], bap[blk][ch],
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qmant[blk][ch], s->nb_coefs[ch]);
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}
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}
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}
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/**
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* Write the AC-3 frame header to the output bitstream.
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*/
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@ -1005,16 +1127,12 @@ static void output_audio_block(AC3EncodeContext *s,
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uint8_t exp_strategy[AC3_MAX_CHANNELS],
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uint8_t encoded_exp[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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uint8_t bap[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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int32_t mdct_coef[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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int8_t exp_shift[AC3_MAX_CHANNELS],
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uint16_t qmant[AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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int block_num)
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{
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int ch, nb_groups, group_size, i, baie, rbnd;
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uint8_t *p;
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uint16_t qmant[AC3_MAX_CHANNELS][AC3_MAX_COEFS];
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int exp0, exp1;
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int mant1_cnt, mant2_cnt, mant4_cnt;
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uint16_t *qmant1_ptr, *qmant2_ptr, *qmant4_ptr;
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int delta0, delta1, delta2;
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for (ch = 0; ch < s->fbw_channels; ch++)
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@ -1117,101 +1235,7 @@ static void output_audio_block(AC3EncodeContext *s,
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put_bits(&s->pb, 1, 0); /* no delta bit allocation */
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put_bits(&s->pb, 1, 0); /* no data to skip */
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/* mantissa encoding : we use two passes to handle the grouping. A
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one pass method may be faster, but it would necessitate to
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modify the output stream. */
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/* first pass: quantize */
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mant1_cnt = mant2_cnt = mant4_cnt = 0;
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qmant1_ptr = qmant2_ptr = qmant4_ptr = NULL;
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for (ch = 0; ch < s->channels; ch++) {
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int b, c, e, v;
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for (i = 0; i < s->nb_coefs[ch]; i++) {
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c = mdct_coef[ch][i];
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e = encoded_exp[ch][i] - exp_shift[ch];
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b = bap[ch][i];
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switch (b) {
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case 0:
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v = 0;
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break;
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case 1:
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v = sym_quant(c, e, 3);
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switch (mant1_cnt) {
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case 0:
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qmant1_ptr = &qmant[ch][i];
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v = 9 * v;
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mant1_cnt = 1;
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break;
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case 1:
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*qmant1_ptr += 3 * v;
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mant1_cnt = 2;
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v = 128;
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break;
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default:
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*qmant1_ptr += v;
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mant1_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 2:
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v = sym_quant(c, e, 5);
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switch (mant2_cnt) {
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case 0:
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qmant2_ptr = &qmant[ch][i];
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v = 25 * v;
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mant2_cnt = 1;
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break;
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case 1:
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*qmant2_ptr += 5 * v;
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mant2_cnt = 2;
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v = 128;
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break;
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default:
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*qmant2_ptr += v;
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mant2_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 3:
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v = sym_quant(c, e, 7);
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break;
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case 4:
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v = sym_quant(c, e, 11);
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switch (mant4_cnt) {
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case 0:
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qmant4_ptr = &qmant[ch][i];
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v = 11 * v;
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mant4_cnt = 1;
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break;
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default:
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*qmant4_ptr += v;
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mant4_cnt = 0;
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v = 128;
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break;
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}
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break;
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case 5:
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v = sym_quant(c, e, 15);
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break;
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case 14:
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v = asym_quant(c, e, 14);
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break;
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case 15:
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v = asym_quant(c, e, 16);
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break;
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default:
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v = asym_quant(c, e, b - 1);
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break;
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}
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qmant[ch][i] = v;
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}
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}
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/* second pass : output the values */
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/* mantissa encoding */
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for (ch = 0; ch < s->channels; ch++) {
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int b, q;
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@ -1313,8 +1337,7 @@ static void output_frame(AC3EncodeContext *s,
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uint8_t exp_strategy[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS],
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uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
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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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uint16_t qmant[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS])
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{
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int blk;
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@ -1324,7 +1347,7 @@ static void output_frame(AC3EncodeContext *s,
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for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
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output_audio_block(s, exp_strategy[blk], encoded_exp[blk],
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bap[blk], mdct_coef[blk], exp_shift[blk], blk);
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bap[blk], qmant[blk], blk);
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}
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output_frame_end(s);
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@ -1346,6 +1369,7 @@ static int ac3_encode_frame(AVCodecContext *avctx,
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uint8_t encoded_exp[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
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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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if (s->bit_alloc.sr_code == 1)
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@ -1359,7 +1383,9 @@ static int ac3_encode_frame(AVCodecContext *avctx,
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compute_bit_allocation(s, bap, encoded_exp, exp_strategy, frame_bits);
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output_frame(s, frame, exp_strategy, encoded_exp, bap, mdct_coef, exp_shift);
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quantize_mantissas(s, mdct_coef, exp_shift, encoded_exp, bap, qmant);
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output_frame(s, frame, exp_strategy, encoded_exp, bap, qmant);
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return s->frame_size;
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}
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