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/*
* h264.c: H.264 bitstream decoding
*
* See the main source file 'xineliboutput.c' for copyright information and
* how to reach the author.
*
* $Id: h264.c,v 1.5 2008-07-29 14:01:36 phintuka Exp $
*
*/
#ifndef LOGDBG
# include <vdr/tools.h>
# include "../logdefs.h"
#endif
#define NOCACHE 1
#include "bitstream.h"
#include "mpeg.h"
#include "h264.h"
int h264_parse_sps(const uint8_t *buf, int len, h264_sps_data_t *sps)
{
br_state br = BR_INIT(buf, len);
int profile_idc, pic_order_cnt_type;
int frame_mbs_only;
int i, j;
profile_idc = br_get_u8(&br);
LOGDBG("H.264 SPS: profile_idc %d", profile_idc);
/* constraint_set0_flag = br_get_bit(br); */
/* constraint_set1_flag = br_get_bit(br); */
/* constraint_set2_flag = br_get_bit(br); */
/* constraint_set3_flag = br_get_bit(br); */
/* reserved = br_get_bits(br,4); */
/* level_idc = br_get_u8(br); */
br_skip_bits(&br, 16);
br_skip_ue_golomb(&br); /* seq_parameter_set_id */
if (profile_idc >= 100) {
if (br_get_ue_golomb(&br) == 3) /* chroma_format_idc */
br_skip_bit(&br); /* residual_colour_transform_flag */
br_skip_ue_golomb(&br); /* bit_depth_luma - 8 */
br_skip_ue_golomb(&br); /* bit_depth_chroma - 8 */
br_skip_bit(&br); /* transform_bypass */
if (br_get_bit(&br)) /* seq_scaling_matrix_present */
for (i = 0; i < 8; i++)
if (br_get_bit(&br)) { /* seq_scaling_list_present */
int last = 8, next = 8, size = (i<6) ? 16 : 64;
for (j = 0; j < size; j++) {
if (next)
next = (last + br_get_se_golomb(&br)) & 0xff;
last = next ?: last;
}
}
}
br_skip_ue_golomb(&br); /* log2_max_frame_num - 4 */
pic_order_cnt_type = br_get_ue_golomb(&br);
if (pic_order_cnt_type == 0)
br_skip_ue_golomb(&br); /* log2_max_poc_lsb - 4 */
else if (pic_order_cnt_type == 1) {
br_skip_bit(&br); /* delta_pic_order_always_zero */
br_skip_se_golomb(&br); /* offset_for_non_ref_pic */
br_skip_se_golomb(&br); /* offset_for_top_to_bottom_field */
j = br_get_ue_golomb(&br); /* num_ref_frames_in_pic_order_cnt_cycle */
for (i = 0; i < j; i++)
br_skip_se_golomb(&br); /* offset_for_ref_frame[i] */
}
br_skip_ue_golomb(&br); /* ref_frames */
br_skip_bit(&br); /* gaps_in_frame_num_allowed */
sps->width /* mbs */ = br_get_ue_golomb(&br) + 1;
sps->height /* mbs */ = br_get_ue_golomb(&br) + 1;
frame_mbs_only = br_get_bit(&br);
LOGDBG("H.264 SPS: pic_width: %u mbs", (unsigned) sps->width);
LOGDBG("H.264 SPS: pic_height: %u mbs", (unsigned) sps->height);
LOGDBG("H.264 SPS: frame only flag: %d", frame_mbs_only);
sps->width *= 16;
sps->height *= 16 * (2-frame_mbs_only);
if (!frame_mbs_only)
if (br_get_bit(&br)) /* mb_adaptive_frame_field_flag */
LOGDBG("H.264 SPS: MBAFF");
br_skip_bit(&br); /* direct_8x8_inference_flag */
if (br_get_bit(&br)) { /* frame_cropping_flag */
uint32_t crop_left = br_get_ue_golomb(&br);
uint32_t crop_right = br_get_ue_golomb(&br);
uint32_t crop_top = br_get_ue_golomb(&br);
uint32_t crop_bottom = br_get_ue_golomb(&br);
LOGDBG("H.264 SPS: cropping %d %d %d %d",
crop_left, crop_top, crop_right, crop_bottom);
sps->width -= 2*(crop_left + crop_right);
if (frame_mbs_only)
sps->height -= 2*(crop_top + crop_bottom);
else
sps->height -= 4*(crop_top + crop_bottom);
}
/* VUI parameters */
sps->pixel_aspect.num = 0;
if (br_get_bit(&br)) { /* vui_parameters_present flag */
if (br_get_bit(&br)) { /* aspect_ratio_info_present */
uint32_t aspect_ratio_idc = br_get_u8(&br);
LOGDBG("H.264 SPS: aspect_ratio_idc %d", aspect_ratio_idc);
if (aspect_ratio_idc == 255 /* Extended_SAR */) {
sps->pixel_aspect.num = br_get_u16(&br); /* sar_width */
sps->pixel_aspect.den = br_get_u16(&br); /* sar_height */
LOGDBG("H.264 SPS: -> sar %dx%d", sps->pixel_aspect.num, sps->pixel_aspect.den);
} else {
static const mpeg_rational_t aspect_ratios[] =
{ /* page 213: */
/* 0: unknown */
{0, 1},
/* 1...16: */
{ 1, 1}, {12, 11}, {10, 11}, {16, 11}, { 40, 33}, {24, 11}, {20, 11}, {32, 11},
{80, 33}, {18, 11}, {15, 11}, {64, 33}, {160, 99}, { 4, 3}, { 3, 2}, { 2, 1}
};
if (aspect_ratio_idc < sizeof(aspect_ratios)/sizeof(aspect_ratios[0])) {
memcpy(&sps->pixel_aspect, &aspect_ratios[aspect_ratio_idc], sizeof(mpeg_rational_t));
LOGDBG("H.264 SPS: -> aspect ratio %d / %d", sps->pixel_aspect.num, sps->pixel_aspect.den);
} else {
LOGMSG("H.264 SPS: aspect_ratio_idc out of range !");
}
}
}
}
LOGDBG("H.264 SPS: -> video size %dx%d, aspect %d:%d",
sps->width, sps->height, sps->pixel_aspect.num, sps->pixel_aspect.den);
if(BR_EOF(&br)) {
LOGDBG("H.264 SPS: not enough data ?");
return 0;
}
return 1;
}
static int h264_nal_unescape(uint8_t *dst, const uint8_t *src, int len)
{
int s = 0, d = 0;
while (s < len) {
if (!src[s] && !src[s+1]) {
/* hit 00 00 xx */
dst[d] = dst[d+1] = 0;
s += 2;
d += 2;
if (src[s] == 3) {
s++; /* 00 00 03 xx --> 00 00 xx */
/*LOGDBG("h264_nal_unescape: hit 00 00 03 %02x", src[s]);*/
if (s >= len)
return d;
} /* else if (src[s] == 0 || src[s] == 1) {
LOGDBG("h264_nal_unescape: invalid NAL sequence 00 00 %02x %02x", src[s], src[s+1]);
return -1;
}*/
}
dst[d++] = src[s++];
}
return d;
}
int h264_get_picture_type(const uint8_t *buf, int len)
{
int i;
for (i = 0; i < len-5; i++) {
if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1 && buf[i + 3] == NAL_AUD) {
uint8_t type = (buf[i + 4] >> 5);
switch (type) {
case 0: case 3: case 5: return I_FRAME;
case 1: case 4: case 6: return P_FRAME;
case 2: case 7: return B_FRAME;
default:;
}
}
}
return NO_PICTURE;
}
int h264_get_video_size(const uint8_t *buf, int len, video_size_t *size)
{
int i;
/* H.264 detection, search for NAL AUD */
if (!IS_NAL_AUD(buf))
return 0;
/* if I-frame, search for NAL SPS */
if (h264_get_picture_type(buf, len) != I_FRAME)
return 0;
/* scan video packet for sequence parameter set */
for (i = 5; i < len-4; i++)
if (buf[i] == 0 && buf[i + 1] == 0 && buf[i + 2] == 1 && (buf[i + 3] & 0x1f) == NAL_SPS) {
uint8_t nal_data[len];
int nal_len;
LOGDBG("H.264: Found NAL SPS at offset %d/%d", i, len);
if (0 < (nal_len = h264_nal_unescape(nal_data, buf+i+4, len-i-4))) {
h264_sps_data_t sps = {0};
if (h264_parse_sps(nal_data, nal_len, &sps)) {
size->width = sps.width;
size->height = sps.height;
memcpy(&size->pixel_aspect, &sps.pixel_aspect, sizeof(mpeg_rational_t));
return 1;
}
LOGMSG("h264_get_video_size: not enough data ?");
}
}
return 0;
}
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