FFmpeg/libavcodec/h264enc.c

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/*
* H.264 encoder
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/common.h"
#include "get_bits.h"
#include "mpegvideo.h"
#include "h264data.h"
/**
* Write out the provided data into a NAL unit.
* @param nal_ref_idc NAL reference IDC
* @param nal_unit_type NAL unit payload type
* @param dest the target buffer, dst+1 == src is allowed as a special case
* @param destsize the length of the dst array
* @param b2 the data which should be escaped
* @return pointer to current position in the output buffer or NULL if an error occurred
*/
static uint8_t *h264_write_nal_unit(int nal_ref_idc, int nal_unit_type, uint8_t *dest, int *destsize,
PutBitContext *b2)
{
PutBitContext b;
int i, destpos, rbsplen, escape_count;
uint8_t *rbsp;
if (nal_unit_type != NAL_END_STREAM)
put_bits(b2,1,1); // rbsp_stop_bit
// Align b2 on a byte boundary
align_put_bits(b2);
rbsplen = put_bits_count(b2)/8;
flush_put_bits(b2);
rbsp = b2->buf;
init_put_bits(&b,dest,*destsize);
put_bits(&b,16,0);
put_bits(&b,16,0x01);
put_bits(&b,1,0); // forbidden zero bit
put_bits(&b,2,nal_ref_idc); // nal_ref_idc
put_bits(&b,5,nal_unit_type); // nal_unit_type
flush_put_bits(&b);
destpos = 5;
escape_count= 0;
for (i=0; i<rbsplen; i+=2)
{
if (rbsp[i]) continue;
if (i>0 && rbsp[i-1]==0)
i--;
if (i+2<rbsplen && rbsp[i+1]==0 && rbsp[i+2]<=3)
{
escape_count++;
i+=2;
}
}
if(escape_count==0)
{
if(dest+destpos != rbsp)
{
memcpy(dest+destpos, rbsp, rbsplen);
*destsize -= (rbsplen+destpos);
}
return dest+rbsplen+destpos;
}
if(rbsplen + escape_count + 1> *destsize)
{
av_log(NULL, AV_LOG_ERROR, "Destination buffer too small!\n");
return NULL;
}
// this should be damn rare (hopefully)
for (i = 0 ; i < rbsplen ; i++)
{
if (i + 2 < rbsplen && (rbsp[i] == 0 && rbsp[i+1] == 0 && rbsp[i+2] < 4))
{
dest[destpos++] = rbsp[i++];
dest[destpos++] = rbsp[i];
dest[destpos++] = 0x03; // emulation prevention byte
}
else
dest[destpos++] = rbsp[i];
}
*destsize -= destpos;
return dest+destpos;
}
static const uint8_t pict_type_to_golomb[7] = {-1, 2, 0, 1, -1, 4, 3};
static const uint8_t intra4x4_cbp_to_golomb[48] = {
3, 29, 30, 17, 31, 18, 37, 8, 32, 38, 19, 9, 20, 10, 11, 2,
16, 33, 34, 21, 35, 22, 39, 4, 36, 40, 23, 5, 24, 6, 7, 1,
41, 42, 43, 25, 44, 26, 46, 12, 45, 47, 27, 13, 28, 14, 15, 0
};
static const uint8_t inter_cbp_to_golomb[48] = {
0, 2, 3, 7, 4, 8, 17, 13, 5, 18, 9, 14, 10, 15, 16, 11,
1, 32, 33, 36, 34, 37, 44, 40, 35, 45, 38, 41, 39, 42, 43, 19,
6, 24, 25, 20, 26, 21, 46, 28, 27, 47, 22, 29, 23, 30, 31, 12
};
#define QUANT_SHIFT 22
static const int quant_coeff[52][16] = {
{ 419430, 258111, 419430, 258111, 258111, 167772, 258111, 167772, 419430, 258111, 419430, 258111, 258111, 167772, 258111, 167772,},
{ 381300, 239675, 381300, 239675, 239675, 149131, 239675, 149131, 381300, 239675, 381300, 239675, 239675, 149131, 239675, 149131,},
{ 322639, 209715, 322639, 209715, 209715, 134218, 209715, 134218, 322639, 209715, 322639, 209715, 209715, 134218, 209715, 134218,},
{ 299593, 186414, 299593, 186414, 186414, 116711, 186414, 116711, 299593, 186414, 299593, 186414, 186414, 116711, 186414, 116711,},
{ 262144, 167772, 262144, 167772, 167772, 107374, 167772, 107374, 262144, 167772, 262144, 167772, 167772, 107374, 167772, 107374,},
{ 233017, 145889, 233017, 145889, 145889, 92564, 145889, 92564, 233017, 145889, 233017, 145889, 145889, 92564, 145889, 92564,},
{ 209715, 129056, 209715, 129056, 129056, 83886, 129056, 83886, 209715, 129056, 209715, 129056, 129056, 83886, 129056, 83886,},
{ 190650, 119837, 190650, 119837, 119837, 74565, 119837, 74565, 190650, 119837, 190650, 119837, 119837, 74565, 119837, 74565,},
{ 161319, 104858, 161319, 104858, 104858, 67109, 104858, 67109, 161319, 104858, 161319, 104858, 104858, 67109, 104858, 67109,},
{ 149797, 93207, 149797, 93207, 93207, 58356, 93207, 58356, 149797, 93207, 149797, 93207, 93207, 58356, 93207, 58356,},
{ 131072, 83886, 131072, 83886, 83886, 53687, 83886, 53687, 131072, 83886, 131072, 83886, 83886, 53687, 83886, 53687,},
{ 116508, 72944, 116508, 72944, 72944, 46282, 72944, 46282, 116508, 72944, 116508, 72944, 72944, 46282, 72944, 46282,},
{ 104858, 64528, 104858, 64528, 64528, 41943, 64528, 41943, 104858, 64528, 104858, 64528, 64528, 41943, 64528, 41943,},
{ 95325, 59919, 95325, 59919, 59919, 37283, 59919, 37283, 95325, 59919, 95325, 59919, 59919, 37283, 59919, 37283,},
{ 80660, 52429, 80660, 52429, 52429, 33554, 52429, 33554, 80660, 52429, 80660, 52429, 52429, 33554, 52429, 33554,},
{ 74898, 46603, 74898, 46603, 46603, 29178, 46603, 29178, 74898, 46603, 74898, 46603, 46603, 29178, 46603, 29178,},
{ 65536, 41943, 65536, 41943, 41943, 26844, 41943, 26844, 65536, 41943, 65536, 41943, 41943, 26844, 41943, 26844,},
{ 58254, 36472, 58254, 36472, 36472, 23141, 36472, 23141, 58254, 36472, 58254, 36472, 36472, 23141, 36472, 23141,},
{ 52429, 32264, 52429, 32264, 32264, 20972, 32264, 20972, 52429, 32264, 52429, 32264, 32264, 20972, 32264, 20972,},
{ 47663, 29959, 47663, 29959, 29959, 18641, 29959, 18641, 47663, 29959, 47663, 29959, 29959, 18641, 29959, 18641,},
{ 40330, 26214, 40330, 26214, 26214, 16777, 26214, 16777, 40330, 26214, 40330, 26214, 26214, 16777, 26214, 16777,},
{ 37449, 23302, 37449, 23302, 23302, 14589, 23302, 14589, 37449, 23302, 37449, 23302, 23302, 14589, 23302, 14589,},
{ 32768, 20972, 32768, 20972, 20972, 13422, 20972, 13422, 32768, 20972, 32768, 20972, 20972, 13422, 20972, 13422,},
{ 29127, 18236, 29127, 18236, 18236, 11570, 18236, 11570, 29127, 18236, 29127, 18236, 18236, 11570, 18236, 11570,},
{ 26214, 16132, 26214, 16132, 16132, 10486, 16132, 10486, 26214, 16132, 26214, 16132, 16132, 10486, 16132, 10486,},
{ 23831, 14980, 23831, 14980, 14980, 9321, 14980, 9321, 23831, 14980, 23831, 14980, 14980, 9321, 14980, 9321,},
{ 20165, 13107, 20165, 13107, 13107, 8389, 13107, 8389, 20165, 13107, 20165, 13107, 13107, 8389, 13107, 8389,},
{ 18725, 11651, 18725, 11651, 11651, 7294, 11651, 7294, 18725, 11651, 18725, 11651, 11651, 7294, 11651, 7294,},
{ 16384, 10486, 16384, 10486, 10486, 6711, 10486, 6711, 16384, 10486, 16384, 10486, 10486, 6711, 10486, 6711,},
{ 14564, 9118, 14564, 9118, 9118, 5785, 9118, 5785, 14564, 9118, 14564, 9118, 9118, 5785, 9118, 5785,},
{ 13107, 8066, 13107, 8066, 8066, 5243, 8066, 5243, 13107, 8066, 13107, 8066, 8066, 5243, 8066, 5243,},
{ 11916, 7490, 11916, 7490, 7490, 4660, 7490, 4660, 11916, 7490, 11916, 7490, 7490, 4660, 7490, 4660,},
{ 10082, 6554, 10082, 6554, 6554, 4194, 6554, 4194, 10082, 6554, 10082, 6554, 6554, 4194, 6554, 4194,},
{ 9362, 5825, 9362, 5825, 5825, 3647, 5825, 3647, 9362, 5825, 9362, 5825, 5825, 3647, 5825, 3647,},
{ 8192, 5243, 8192, 5243, 5243, 3355, 5243, 3355, 8192, 5243, 8192, 5243, 5243, 3355, 5243, 3355,},
{ 7282, 4559, 7282, 4559, 4559, 2893, 4559, 2893, 7282, 4559, 7282, 4559, 4559, 2893, 4559, 2893,},
{ 6554, 4033, 6554, 4033, 4033, 2621, 4033, 2621, 6554, 4033, 6554, 4033, 4033, 2621, 4033, 2621,},
{ 5958, 3745, 5958, 3745, 3745, 2330, 3745, 2330, 5958, 3745, 5958, 3745, 3745, 2330, 3745, 2330,},
{ 5041, 3277, 5041, 3277, 3277, 2097, 3277, 2097, 5041, 3277, 5041, 3277, 3277, 2097, 3277, 2097,},
{ 4681, 2913, 4681, 2913, 2913, 1824, 2913, 1824, 4681, 2913, 4681, 2913, 2913, 1824, 2913, 1824,},
{ 4096, 2621, 4096, 2621, 2621, 1678, 2621, 1678, 4096, 2621, 4096, 2621, 2621, 1678, 2621, 1678,},
{ 3641, 2280, 3641, 2280, 2280, 1446, 2280, 1446, 3641, 2280, 3641, 2280, 2280, 1446, 2280, 1446,},
{ 3277, 2016, 3277, 2016, 2016, 1311, 2016, 1311, 3277, 2016, 3277, 2016, 2016, 1311, 2016, 1311,},
{ 2979, 1872, 2979, 1872, 1872, 1165, 1872, 1165, 2979, 1872, 2979, 1872, 1872, 1165, 1872, 1165,},
{ 2521, 1638, 2521, 1638, 1638, 1049, 1638, 1049, 2521, 1638, 2521, 1638, 1638, 1049, 1638, 1049,},
{ 2341, 1456, 2341, 1456, 1456, 912, 1456, 912, 2341, 1456, 2341, 1456, 1456, 912, 1456, 912,},
{ 2048, 1311, 2048, 1311, 1311, 839, 1311, 839, 2048, 1311, 2048, 1311, 1311, 839, 1311, 839,},
{ 1820, 1140, 1820, 1140, 1140, 723, 1140, 723, 1820, 1140, 1820, 1140, 1140, 723, 1140, 723,},
{ 1638, 1008, 1638, 1008, 1008, 655, 1008, 655, 1638, 1008, 1638, 1008, 1008, 655, 1008, 655,},
{ 1489, 936, 1489, 936, 936, 583, 936, 583, 1489, 936, 1489, 936, 936, 583, 936, 583,},
{ 1260, 819, 1260, 819, 819, 524, 819, 524, 1260, 819, 1260, 819, 819, 524, 819, 524,},
{ 1170, 728, 1170, 728, 728, 456, 728, 456, 1170, 728, 1170, 728, 728, 456, 728, 456,},
};
//FIXME need to check that this does not overflow signed 32 bit for low qp, I am not sure, it's very close
//FIXME check that gcc inlines this (and optimizes intra & separate_dc stuff away)
static inline int quantize_c(DCTELEM *block, uint8_t *scantable, int qscale,
int intra, int separate_dc)
{
int i;
const int * const quant_table = quant_coeff[qscale];
const int bias = intra ? (1 << QUANT_SHIFT) / 3 : (1 << QUANT_SHIFT) / 6;
const unsigned int threshold1 = (1 << QUANT_SHIFT) - bias - 1;
const unsigned int threshold2 = (threshold1 << 1);
int last_non_zero;
if (separate_dc) {
if (qscale <= 18) {
//avoid overflows
const int dc_bias = intra ? (1 << (QUANT_SHIFT - 2)) / 3 : (1 << (QUANT_SHIFT - 2)) / 6;
const unsigned int dc_threshold1 = (1 << (QUANT_SHIFT - 2)) - dc_bias - 1;
const unsigned int dc_threshold2 = (dc_threshold1 << 1);
int level = block[0]*quant_coeff[qscale+18][0];
if (((unsigned)(level + dc_threshold1)) > dc_threshold2) {
if (level > 0) {
level = (dc_bias + level) >> (QUANT_SHIFT - 2);
block[0] = level;
} else {
level = (dc_bias - level) >> (QUANT_SHIFT - 2);
block[0] = -level;
}
// last_non_zero = i;
} else {
block[0] = 0;
}
} else {
const int dc_bias = intra ? (1 << (QUANT_SHIFT + 1)) / 3 : (1 << (QUANT_SHIFT + 1)) / 6;
const unsigned int dc_threshold1 = (1 << (QUANT_SHIFT + 1)) - dc_bias - 1;
const unsigned int dc_threshold2 = (dc_threshold1 << 1);
int level = block[0]*quant_table[0];
if (((unsigned)(level + dc_threshold1)) > dc_threshold2) {
if (level > 0) {
level = (dc_bias + level) >> (QUANT_SHIFT + 1);
block[0] = level;
} else {
level = (dc_bias - level) >> (QUANT_SHIFT + 1);
block[0] = -level;
}
// last_non_zero = i;
} else {
block[0] = 0;
}
}
last_non_zero = 0;
i = 1;
} else {
last_non_zero = -1;
i = 0;
}
for (; i < 16; i++) {
const int j = scantable[i];
int level = block[j]*quant_table[j];
// if ( bias+level >= (1 << (QMAT_SHIFT - 3))
// || bias-level >= (1 << (QMAT_SHIFT - 3))) {
if (((unsigned)(level + threshold1)) > threshold2) {
if (level > 0) {
level = (bias + level) >> QUANT_SHIFT;
block[j] = level;
} else {
level = (bias - level) >> QUANT_SHIFT;
block[j] = -level;
}
last_non_zero = i;
} else {
block[j] = 0;
}
}
return last_non_zero;
}