mirror of https://git.ffmpeg.org/ffmpeg.git
Use a single value for SNR offset in the bit allocation search rather than
the separate coarse and fine values. Originally committed as revision 26010 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
parent
70fcd7ea80
commit
a0d763fc88
|
@ -923,12 +923,12 @@ static int bit_alloc(AC3EncodeContext *s,
|
||||||
int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS],
|
int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS],
|
||||||
int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
|
int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
|
||||||
uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
|
uint8_t bap[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS],
|
||||||
int coarse_snr_offset, int fine_snr_offset)
|
int snr_offset)
|
||||||
{
|
{
|
||||||
int blk, ch;
|
int blk, ch;
|
||||||
int snr_offset, mantissa_bits;
|
int mantissa_bits;
|
||||||
|
|
||||||
snr_offset = (((coarse_snr_offset - 15) << 4) + fine_snr_offset) << 2;
|
snr_offset = (snr_offset - 240) << 2;
|
||||||
|
|
||||||
mantissa_bits = 0;
|
mantissa_bits = 0;
|
||||||
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
|
for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
|
||||||
|
@ -947,8 +947,6 @@ static int bit_alloc(AC3EncodeContext *s,
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
||||||
#define SNR_INC1 4
|
|
||||||
|
|
||||||
/**
|
/**
|
||||||
* Perform bit allocation search.
|
* Perform bit allocation search.
|
||||||
* Finds the SNR offset value that maximizes quality and fits in the specified
|
* Finds the SNR offset value that maximizes quality and fits in the specified
|
||||||
|
@ -962,7 +960,7 @@ static int compute_bit_allocation(AC3EncodeContext *s,
|
||||||
{
|
{
|
||||||
int ch;
|
int ch;
|
||||||
int bits_left;
|
int bits_left;
|
||||||
int coarse_snr_offset, fine_snr_offset;
|
int snr_offset;
|
||||||
uint8_t bap1[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
|
uint8_t bap1[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
|
||||||
int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
|
int16_t psd[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_MAX_COEFS];
|
||||||
int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];
|
int16_t mask[AC3_MAX_BLOCKS][AC3_MAX_CHANNELS][AC3_CRITICAL_BANDS];
|
||||||
|
@ -977,42 +975,40 @@ static int compute_bit_allocation(AC3EncodeContext *s,
|
||||||
offset until we can pack everything in the requested frame size */
|
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);
|
||||||
coarse_snr_offset = s->coarse_snr_offset;
|
snr_offset = s->coarse_snr_offset << 4;
|
||||||
while (coarse_snr_offset >= 0 &&
|
while (snr_offset >= 0 &&
|
||||||
bit_alloc(s, mask, psd, bap, coarse_snr_offset, 0) > bits_left)
|
bit_alloc(s, mask, psd, bap, snr_offset) > bits_left)
|
||||||
coarse_snr_offset -= SNR_INC1;
|
snr_offset -= 64;
|
||||||
if (coarse_snr_offset < 0) {
|
if (snr_offset < 0) {
|
||||||
return AVERROR(EINVAL);
|
return AVERROR(EINVAL);
|
||||||
}
|
}
|
||||||
while (coarse_snr_offset + SNR_INC1 <= 63 &&
|
while (snr_offset + 64 <= 1023 &&
|
||||||
bit_alloc(s, mask, psd, bap1,
|
bit_alloc(s, mask, psd, bap1,
|
||||||
coarse_snr_offset + SNR_INC1, 0) <= bits_left) {
|
snr_offset + 64) <= bits_left) {
|
||||||
coarse_snr_offset += SNR_INC1;
|
snr_offset += 64;
|
||||||
memcpy(bap, bap1, sizeof(bap1));
|
memcpy(bap, bap1, sizeof(bap1));
|
||||||
}
|
}
|
||||||
while (coarse_snr_offset + 1 <= 63 &&
|
while (snr_offset + 16 <= 1023 &&
|
||||||
bit_alloc(s, mask, psd, bap1, coarse_snr_offset + 1, 0) <= bits_left) {
|
bit_alloc(s, mask, psd, bap1, snr_offset + 16) <= bits_left) {
|
||||||
coarse_snr_offset++;
|
snr_offset += 16;
|
||||||
|
memcpy(bap, bap1, sizeof(bap1));
|
||||||
|
}
|
||||||
|
while (snr_offset + 4 <= 1023 &&
|
||||||
|
bit_alloc(s, mask, psd, bap1,
|
||||||
|
snr_offset + 4) <= bits_left) {
|
||||||
|
snr_offset += 4;
|
||||||
|
memcpy(bap, bap1, sizeof(bap1));
|
||||||
|
}
|
||||||
|
while (snr_offset + 1 <= 1023 &&
|
||||||
|
bit_alloc(s, mask, psd, bap1,
|
||||||
|
snr_offset + 1) <= bits_left) {
|
||||||
|
snr_offset++;
|
||||||
memcpy(bap, bap1, sizeof(bap1));
|
memcpy(bap, bap1, sizeof(bap1));
|
||||||
}
|
}
|
||||||
|
|
||||||
fine_snr_offset = 0;
|
s->coarse_snr_offset = snr_offset >> 4;
|
||||||
while (fine_snr_offset + SNR_INC1 <= 15 &&
|
|
||||||
bit_alloc(s, mask, psd, bap1,
|
|
||||||
coarse_snr_offset, fine_snr_offset + SNR_INC1) <= bits_left) {
|
|
||||||
fine_snr_offset += SNR_INC1;
|
|
||||||
memcpy(bap, bap1, sizeof(bap1));
|
|
||||||
}
|
|
||||||
while (fine_snr_offset + 1 <= 15 &&
|
|
||||||
bit_alloc(s, mask, psd, bap1,
|
|
||||||
coarse_snr_offset, fine_snr_offset + 1) <= bits_left) {
|
|
||||||
fine_snr_offset++;
|
|
||||||
memcpy(bap, bap1, sizeof(bap1));
|
|
||||||
}
|
|
||||||
|
|
||||||
s->coarse_snr_offset = coarse_snr_offset;
|
|
||||||
for (ch = 0; ch < s->channels; ch++)
|
for (ch = 0; ch < s->channels; ch++)
|
||||||
s->fine_snr_offset[ch] = fine_snr_offset;
|
s->fine_snr_offset[ch] = snr_offset & 0xF;
|
||||||
|
|
||||||
return 0;
|
return 0;
|
||||||
}
|
}
|
||||||
|
|
Loading…
Reference in New Issue