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bitstream_info.c
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bitstream_info.c
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/*
* bitstream_info.h
* Created by Graham Booker on 1/6/07.
*
* This file is part of Perian.
*
* This library 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.
*
* This library 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 "bitstream_info.h"
#include <AudioToolbox/AudioToolbox.h>
#include <QuickTime/QuickTime.h>
#import "ac3tab.h"
#import "CommonUtils.h"
//ffmpeg's struct Picture conflicts with QuickDraw's
#define Picture MPEGPICTURE
#include "avcodec.h"
#include "bswap.h"
#include "libavutil/intmath.h"
#include "libavutil/internal.h"
#include "mpegvideo.h"
#include "parser.h"
#include "golomb.h"
#include "mpeg4video.h"
#include "mpeg4video_parser.h"
#include "Codecprintf.h"
#include "CodecIDs.h"
#undef malloc
#undef free
static const int nfchans_tbl[8] = { 2, 1, 2, 3, 3, 4, 4, 5 };
static const int ac3_layout_no_lfe[8] = {
kAudioChannelLayoutTag_Stereo,
kAudioChannelLayoutTag_Mono,
kAudioChannelLayoutTag_Stereo,
kAudioChannelLayoutTag_ITU_3_0,
kAudioChannelLayoutTag_ITU_2_1,
kAudioChannelLayoutTag_ITU_3_1,
kAudioChannelLayoutTag_ITU_2_2,
kAudioChannelLayoutTag_ITU_3_2};
static const int ac3_layout_lfe[8] = {
kAudioChannelLayoutTag_DVD_4,
kAudioChannelLayoutTag_Mono, //No layout for this, hopefully we never have it
kAudioChannelLayoutTag_DVD_4,
kAudioChannelLayoutTag_DVD_10,
kAudioChannelLayoutTag_DVD_5,
kAudioChannelLayoutTag_DVD_11,
kAudioChannelLayoutTag_DVD_6,
kAudioChannelLayoutTag_ITU_3_2_1};
static const uint16_t ac3_freqs[3] = { 48000, 44100, 32000 };
static const uint16_t ac3_bitratetab[] = {32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384, 448, 512, 576, 640};
static const uint8_t ac3_halfrate[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 3};
/* From: http://svn.mplayerhq.hu/ac3/ (LGPL)
* Synchronize to ac3 bitstream.
* This function searches for the syncword '0xb77'.
*
* @param buf Pointer to "probable" ac3 bitstream buffer
* @param buf_size Size of buffer
* @return Returns the position where syncword is found, -1 if no syncword is found
*/
static int ac3_synchronize(uint8_t *buf, int buf_size)
{
int i;
for (i = 0; i < buf_size - 1; i++)
if (buf[i] == 0x0b && buf[i + 1] == 0x77)
return i;
return -1;
}
/* A lot of this was stolen from: http://svn.mplayerhq.hu/ac3/ (LGPL)
* Fill info from an ac3 stream
*
* @param asdb Pointer to the AudioStreamBasicDescription to fill
* @param acl Pointer to the AudioChannelLayout to fill
* @param buffer Pointer to the buffer data to scan
* @param buff_size Size of the buffer
* @return 1 if successfull, 0 otherwise
*/
int parse_ac3_bitstream(AudioStreamBasicDescription *asbd, AudioChannelLayout *acl, uint8_t *buffer, int buff_size)
{
int offset = ac3_synchronize(buffer, buff_size);
if(offset == -1)
return 0;
if(buff_size < offset + 7)
return 0;
uint8_t fscod_and_frmsizecod = buffer[offset + 4];
uint8_t fscod = fscod_and_frmsizecod >> 6;
uint8_t frmsizecod = fscod_and_frmsizecod & 0x3f;
if(frmsizecod >= 38)
return 0;
uint8_t bsid = buffer[offset + 5] >> 3;
if(bsid >= 0x12)
return 0;
uint8_t acmod = buffer[offset + 6] >> 5;
uint8_t shift = 4;
if(acmod & 0x01 && acmod != 0x01)
shift -= 2;
if(acmod & 0x04)
shift -= 2;
if(acmod == 0x02)
shift -= 2;
uint8_t lfe = (buffer[offset + 6] >> shift) & 0x01;
/* This is a valid frame!!! */
uint16_t bitrate = ac3_bitratetab[frmsizecod >> 1];
uint8_t half = ac3_halfrate[bsid];
int sample_rate = ac3_freqs[fscod] >> half;
int framesize = 0;
switch (fscod) {
case 0:
framesize = 4 * bitrate;
break;
case 1:
framesize = (320 * bitrate / 147 + (frmsizecod & 1 ? 1 : 0)) * 2;
break;
case 2:
framesize = 6 * bitrate;
break;
default:
break;
}
shift = 0;
if(bsid > 8)
shift = bsid - 8;
/* Setup the AudioStreamBasicDescription and AudioChannelLayout */
memset(asbd, 0, sizeof(AudioStreamBasicDescription));
asbd->mSampleRate = sample_rate >> shift;
asbd->mFormatID = kAudioFormatAC3MS;
asbd->mChannelsPerFrame = nfchans_tbl[acmod] + lfe;
memset(acl, 0, sizeof(AudioChannelLayout));
if(lfe)
acl->mChannelLayoutTag = ac3_layout_lfe[acmod];
else
acl->mChannelLayoutTag = ac3_layout_no_lfe[acmod];
return 1;
}
static int parse_mpeg4_extra(FFusionParserContext *parser, const uint8_t *buf, int buf_size)
{
ParseContext1 *pc1 = (ParseContext1 *)parser->pc->priv_data;
pc1->pc.frame_start_found = 0;
MpegEncContext *s = pc1->enc;
GetBitContext gb1, *gb = &gb1;
s->avctx = parser->avctx;
s->current_picture_ptr = &s->current_picture;
init_get_bits(gb, buf, 8 * buf_size);
ff_mpeg4_decode_picture_header(s, gb);
return 1;
}
/*
* Long story short, FFMpeg's parsers suck for our use. This function parses an mpeg4 bitstream,
* and assumes that it is given at least a full frame of data.
* @param parser A FFusionParserContext structure containg all our info
* @param buf The buffer to parse
* @param buf_size Size of the input buffer
* @param out_buf_size The number of bytes present in the first frame of data
* @param type The frame Type: FF_*_TYPE
* @param pts The PTS of the frame
* @return 1 if a frame is found, 0 otherwise
*/
static int parse_mpeg4_stream(FFusionParserContext *parser, const uint8_t *buf, int buf_size, int *out_buf_size, int *type, int *skippable, int *skipped)
{
ParseContext1 *pc1 = (ParseContext1 *)parser->pc->priv_data;
pc1->pc.frame_start_found = 0;
int endOfFrame = ff_mpeg4_find_frame_end(&(pc1->pc), buf, buf_size);
MpegEncContext *s = pc1->enc;
GetBitContext gb1, *gb = &gb1;
s->avctx = parser->avctx;
s->current_picture_ptr = &s->current_picture;
init_get_bits(gb, buf, 8 * buf_size);
int parse_res = ff_mpeg4_decode_picture_header(s, gb);
if(parse_res == FRAME_SKIPPED) {
*out_buf_size = buf_size;
*type = FF_P_TYPE;
*skippable = 1;
*skipped = 1;
}
if(parse_res != 0)
return 0;
*type = s->pict_type;
*skippable = (*type == FF_B_TYPE);
*skipped = 0;
#if 0 /*this was an attempt to figure out the PTS information and detect an out of order P frame before we hit its B frame */
int64_t *lastPtsPtr = (int64_t *)parser->internalContext;
int64_t lastPts = *lastPtsPtr;
int64_t currentPts = s->current_picture.pts;
switch(s->pict_type)
{
case FF_I_TYPE:
*lastPtsPtr = currentPts;
*precedesAPastFrame = 0;
break;
case FF_P_TYPE:
if(currentPts > lastPts + 1)
*precedesAPastFrame = 1;
else
*precedesAPastFrame = 0;
*lastPtsPtr = currentPts;
break;
case FF_B_TYPE:
*precedesAPastFrame = 0;
break;
default:
break;
}
#endif
if(endOfFrame == END_NOT_FOUND)
*out_buf_size = buf_size;
else
*out_buf_size = endOfFrame;
return 1;
}
static int parse_mpeg12_stream(FFusionParserContext *ffparser, const uint8_t *buf, int buf_size, int *out_buf_size, int *type, int *skippable, int *skipped)
{
const uint8_t *out_unused;
int size_unused;
AVCodecParser *parser = ffparser->pc->parser;
parser->parser_parse(ffparser->pc, ffparser->avctx, &out_unused, &size_unused, buf, buf_size);
*out_buf_size = buf_size;
*type = ffparser->pc->pict_type;
*skippable = *type == FF_B_TYPE;
*skipped = 0;
return 1;
}
extern AVCodecParser mpeg4video_parser;
static FFusionParser ffusionMpeg4VideoParser = {
&mpeg4video_parser,
0,
NULL,
parse_mpeg4_extra,
parse_mpeg4_stream,
};
extern AVCodecParser mpegvideo_parser;
static FFusionParser ffusionMpeg12VideoParser = {
&mpegvideo_parser,
0,
NULL,
NULL,
parse_mpeg12_stream,
};
typedef struct H264ParserContext_s
{
int is_avc;
int nal_length_size;
int prevPts;
int profile_idc;
int level_idc;
int poc_type;
int log2_max_frame_num;
int frame_mbs_only_flag;
int num_reorder_frames;
int pic_order_present_flag;
int log2_max_poc_lsb;
int poc_msb;
int prev_poc_lsb;
int delta_pic_order_always_zero_flag;
int offset_for_non_ref_pic;
int num_ref_frames_in_pic_order_cnt_cycle;
int sum_of_offset_for_ref_frames;
int chroma_format_idc;
int gaps_in_frame_num_value_allowed_flag;
}H264ParserContext;
static int decode_nal(const uint8_t *buf, int buf_size, uint8_t *out_buf, int *out_buf_size, int *type, int *nal_ref_idc)
{
int i;
int outIndex = 0;
int numNulls = 0;
for(i=1; i<buf_size; i++)
{
if(buf[i] == 0)
numNulls++;
else if(numNulls == 2)
{
numNulls = 0;
if(buf[i] < 3)
{
/* end of nal */
outIndex -= 2;
break;
}
else if(buf[i] == 3)
/* This is just a simple escape of 0x00 00 03 */
continue;
}
else
numNulls = 0;
out_buf[outIndex] = buf[i];
outIndex++;
}
if(outIndex <= 0)
return 0;
*type = buf[0] & 0x1f;
*nal_ref_idc = (buf[0] >> 5) & 0x03;
*out_buf_size = outIndex;
return 1;
}
static void skip_scaling_list(GetBitContext *gb, int size){
int i, next = 8, last = 8;
if(get_bits1(gb)) /* matrix not written, we use the predicted one */
for(i=0;i<size;i++){
if(next)
next = (last + get_se_golomb(gb)) & 0xff;
if(!i && !next){ /* matrix not written, we use the preset one */
break;
}
last = next ? next : last;
}
}
static void skip_scaling_matrices(GetBitContext *gb){
if(get_bits1(gb)){
skip_scaling_list(gb, 16); // Intra, Y
skip_scaling_list(gb, 16); // Intra, Cr
skip_scaling_list(gb, 16); // Intra, Cb
skip_scaling_list(gb, 16); // Inter, Y
skip_scaling_list(gb, 16); // Inter, Cr
skip_scaling_list(gb, 16); // Inter, Cb
skip_scaling_list(gb, 64); // Intra, Y
skip_scaling_list(gb, 64); // Inter, Y
}
}
static void skip_hrd_parameters(GetBitContext *gb)
{
int cpb_cnt_minus1 = get_ue_golomb(gb);
get_bits(gb, 4); //bit_rate_scale
get_bits(gb, 4); //cpb_size_scale
int i;
for(i=0; i<=cpb_cnt_minus1; i++)
{
get_ue_golomb(gb); //bit_rate_value_minus1[i]
get_ue_golomb(gb); //cpb_size_value_minus1[i]
get_bits1(gb); //cbr_flag[i]
}
get_bits(gb, 5); //initial_cpb_removal_delay_length_minus1
get_bits(gb, 5); //cpb_removal_delay_length_minus1
get_bits(gb, 5); //dpb_output_delay_length_minus1
get_bits(gb, 5); //time_offset_length
}
static void decode_sps(H264ParserContext *context, const uint8_t *buf, int buf_size)
{
GetBitContext getbit, *gb = &getbit;
init_get_bits(gb, buf, 8 * buf_size);
context->profile_idc= get_bits(gb, 8);
get_bits1(gb); //constraint_set0_flag
get_bits1(gb); //constraint_set1_flag
get_bits1(gb); //constraint_set2_flag
get_bits1(gb); //constraint_set3_flag
get_bits(gb, 4); //reserved
context->level_idc = get_bits(gb, 8); //level_idc
get_ue_golomb(gb); //seq_parameter_set_id
if(context->profile_idc >= 100)
{
context->chroma_format_idc = get_ue_golomb(gb);
//high profile
if(context->chroma_format_idc == 3) //chroma_format_idc
get_bits1(gb); //residual_color_transfrom_flag
get_ue_golomb(gb); //bit_depth_luma_minus8
get_ue_golomb(gb); //bit_depth_chroma_minus8
get_bits1(gb); //transform_bypass
skip_scaling_matrices(gb);
}
context->log2_max_frame_num = get_ue_golomb(gb) + 4;
context->poc_type = get_ue_golomb(gb);
if(context->poc_type == 0)
context->log2_max_poc_lsb = get_ue_golomb(gb) + 4;
else if(context->poc_type == 1)
{
int i;
context->delta_pic_order_always_zero_flag = get_bits1(gb);
context->offset_for_non_ref_pic = get_se_golomb(gb);
get_se_golomb(gb); //offset_for_top_to_bottom_field
context->num_ref_frames_in_pic_order_cnt_cycle = get_ue_golomb(gb);
context->sum_of_offset_for_ref_frames = 0;
for(i=0; i<context->num_ref_frames_in_pic_order_cnt_cycle; i++)
context->sum_of_offset_for_ref_frames += get_se_golomb(gb); //offset_for_ref_frame[i]
}
get_ue_golomb(gb); //num_ref_frames
context->gaps_in_frame_num_value_allowed_flag = get_bits1(gb); //gaps_in_frame_num_value_allowed_flag
get_ue_golomb(gb); //pic_width_in_mbs_minus1
get_ue_golomb(gb); //pic_height_in_map_units_minus1
int mbs_only = get_bits1(gb);
context->frame_mbs_only_flag = mbs_only;
#if 1 //This is a test to get num_reorder_frames
if(!mbs_only)
get_bits1(gb); //mb_adaptive_frame_field_flag
get_bits1(gb); //direct_8x8_inference_flag
if(get_bits1(gb)) //frame_cropping_flag
{
get_ue_golomb(gb); //frame_crop_left_offset
get_ue_golomb(gb); //frame_crop_right_offset
get_ue_golomb(gb); //frame_crop_top_offset
get_ue_golomb(gb); //frame_crop_bottom_offset
}
if(get_bits1(gb)) //vui_parameters_present_flag
{
if(get_bits1(gb)) //aspect_ratio_info_present_flag
{
if(get_bits(gb, 8) == 255) //aspect_ratio_idc
{
get_bits(gb, 16); //sar_width
get_bits(gb, 16); //sar_height
}
}
if(get_bits1(gb)) //overscan_info_present_flag
get_bits1(gb); //overscan_appropriate_flag
if(get_bits1(gb)) //video_signal_type_present_flag
{
get_bits(gb, 3); //video_format
get_bits1(gb); //video_full_range_flag
if(get_bits1(gb)) //colour_description_present_flag
{
get_bits(gb, 8); //colour_primaries
get_bits(gb, 8); //transfer_characteristics
get_bits(gb, 8); //matrix_coefficients
}
}
if(get_bits1(gb)) //chroma_loc_info_present_flag
{
get_ue_golomb(gb); //chroma_sample_loc_type_top_field
get_ue_golomb(gb); //chroma_sample_loc_type_bottom_field
}
if(get_bits1(gb)) //timing_info_present_flag
{
get_bits(gb, 32); //num_units_in_tick
get_bits(gb, 32); //time_scale
get_bits1(gb); //fixed_frame_rate_flag
}
int nal_hrd_parameters_present_flag = get_bits1(gb);
if(nal_hrd_parameters_present_flag)
{
skip_hrd_parameters(gb);
}
int vcl_hrd_parameters_present_flag = get_bits1(gb);
if(vcl_hrd_parameters_present_flag)
{
skip_hrd_parameters(gb);
}
if(nal_hrd_parameters_present_flag || vcl_hrd_parameters_present_flag)
get_bits1(gb); //low_delay_hrd_flag
get_bits1(gb); //pic_struct_present_flag
if(get_bits1(gb)) //bitstream_restriction_flag
{
get_bits1(gb); //motion_vectors_over_pic_boundaries_flag
get_ue_golomb(gb); //max_bytes_per_pic_denom
get_ue_golomb(gb); //max_bits_per_mb_denom
get_ue_golomb(gb); //log2_max_mv_length_horizontal
get_ue_golomb(gb); //log2_max_mv_length_vertical
context->num_reorder_frames = get_ue_golomb(gb);
get_ue_golomb(gb); //max_dec_frame_buffering
}
}
#endif
}
static void decode_pps(H264ParserContext *context, const uint8_t *buf, int buf_size)
{
GetBitContext getbit, *gb = &getbit;
init_get_bits(gb, buf, 8 * buf_size);
get_ue_golomb(gb); //pic_parameter_set_id
get_ue_golomb(gb); //seq_parameter_set_id
get_bits1(gb); //entropy_coding_mode_flag
context->pic_order_present_flag = get_bits1(gb);
}
static int inline decode_slice_header(H264ParserContext *context, const uint8_t *buf, int buf_size, int nal_ref_idc, int nal_type, int just_type, int *type, int *pts)
{
GetBitContext getbit, *gb = &getbit;
int slice_type;
int field_pic_flag = 0;
int bottom_field_flag = 0;
int frame_number;
// static const uint8_t slice_type_map[5] = {FF_P_TYPE, FF_B_TYPE, FF_I_TYPE, FF_SP_TYPE, FF_SI_TYPE};
static const uint8_t slice_type_map[5] = {FF_P_TYPE, FF_P_TYPE, FF_I_TYPE, FF_SP_TYPE, FF_SI_TYPE};
init_get_bits(gb, buf, 8 * buf_size);
get_ue_golomb(gb); //first_mb_in_slice
slice_type = get_ue_golomb(gb);
if(slice_type > 9)
return 0;
if(slice_type > 4)
slice_type -= 5;
*type = slice_type_map[slice_type];
if(just_type)
return 1;
get_ue_golomb(gb); //pic_parameter_set_id
frame_number = get_bits(gb, context->log2_max_frame_num);
if(!context->frame_mbs_only_flag)
{
field_pic_flag = get_bits1(gb);
if(field_pic_flag)
{
bottom_field_flag = get_bits1(gb);
}
}
if(nal_type == 5)
get_ue_golomb(gb); //idr_pic_id
if(context->poc_type == 0)
{
int pts_lsb = get_bits(gb, context->log2_max_poc_lsb);
int delta_pic_order_cnt_bottom = 0;
int maxPicOrderCntLsb = 1 << context->log2_max_poc_lsb;
int pic_order_msb;
if(context->pic_order_present_flag && !field_pic_flag)
delta_pic_order_cnt_bottom = get_se_golomb(gb);
if((pts_lsb < context->prev_poc_lsb) && (context->prev_poc_lsb - pts_lsb) >= maxPicOrderCntLsb)
pic_order_msb = context->poc_msb + maxPicOrderCntLsb;
else if((pts_lsb > context->prev_poc_lsb) && (pts_lsb - context->prev_poc_lsb) > maxPicOrderCntLsb)
pic_order_msb = context->poc_msb - maxPicOrderCntLsb;
else
pic_order_msb = context->poc_msb;
context->poc_msb = pic_order_msb;
*pts = pic_order_msb + pts_lsb;
if(delta_pic_order_cnt_bottom < 0)
*pts += delta_pic_order_cnt_bottom;
}
else if(context->poc_type == 1 && !context->delta_pic_order_always_zero_flag)
{
int delta_pic_order_cnt[2] = {0, 0};
delta_pic_order_cnt[0] = get_se_golomb(gb);
if(context->pic_order_present_flag && !field_pic_flag)
delta_pic_order_cnt[1] = get_se_golomb(gb);
int frame_num_offset = 0; //I think this is wrong, but the pts code isn't used anywhere, so no harm yet and this removes a warning.
int abs_frame_num = 0;
int num_ref_frames_in_pic_order_cnt_cycle = context->num_ref_frames_in_pic_order_cnt_cycle;
if(num_ref_frames_in_pic_order_cnt_cycle != 0)
abs_frame_num = frame_num_offset + frame_number;
if(nal_ref_idc == 0 && abs_frame_num > 0)
abs_frame_num--;
int expected_delta_per_poc_cycle = context->sum_of_offset_for_ref_frames;
int expectedpoc = 0;
if(abs_frame_num > 0)
{
int poc_cycle_cnt = (abs_frame_num - 1) / num_ref_frames_in_pic_order_cnt_cycle;
expectedpoc = poc_cycle_cnt * expected_delta_per_poc_cycle + context->sum_of_offset_for_ref_frames;
}
if(nal_ref_idc == 0)
expectedpoc = expectedpoc + context->offset_for_non_ref_pic;
*pts = expectedpoc + delta_pic_order_cnt[0];
}
return 1;
}
#define NAL_PEEK_SIZE 32
static int inline decode_nals(H264ParserContext *context, const uint8_t *buf, int buf_size, int *type, int *skippable)
{
int nalsize = 0;
int buf_index = 0;
int ret = 0;
int pts_decoded = 0;
int lowestType = 20;
*skippable = 1;
#if 0 /*this was an attempt to figure out the PTS information and detect an out of order P frame before we hit its B frame */
if(context->poc_type == 2)
{
//decode and display order are the same
pts_decoded = 1;
*precedesAPastFrame = 0;
}
#endif
for(;;)
{
if(context->is_avc)
{
if(buf_index >= buf_size)
break;
nalsize = 0;
switch (context->nal_length_size) {
case 1:
nalsize = buf[buf_index];
buf_index++;
break;
case 2:
nalsize = (buf[buf_index] << 8) | buf[buf_index+1];
buf_index += 2;
break;
case 3:
nalsize = (buf[buf_index] << 16) | (buf[buf_index+1] << 8) | buf[buf_index + 2];
buf_index += 3;
break;
case 4:
nalsize = (buf[buf_index] << 24) | (buf[buf_index+1] << 16) | (buf[buf_index + 2] << 8) | buf[buf_index + 3];
buf_index += 4;
break;
default:
break;
}
if(nalsize <= 1 || nalsize > buf_size)
{
if(nalsize == 1)
{
buf_index++;
continue;
}
else
break;
}
}
else
{
int num_nuls = 0;
int start_offset = 0;
//do start code prefix search
for(; buf_index < buf_size; buf_index++)
{
if(buf[buf_index] == 0)
num_nuls++;
else
{
if(num_nuls >= 2 && buf[buf_index] == 1)
break;
num_nuls = 0;
}
}
start_offset = buf_index + 1;
//do start code prefix search
for(buf_index++; buf_index < buf_size; buf_index++)
{
if(buf[buf_index] == 0)
{
if(num_nuls == 2)
break;
num_nuls++;
}
else
{
if(num_nuls == 2 && buf[buf_index] == 1)
break;
num_nuls = 0;
}
}
if(start_offset >= buf_size)
//no more
break;
nalsize = buf_index - start_offset;
if(buf_index < buf_size)
//Take off the next NAL's startcode
nalsize -= 2;
//skip the start code
buf_index = start_offset;
}
uint8_t partOfNal[NAL_PEEK_SIZE];
int decodedNalSize, nalType;
int nal_ref_idc;
int slice_type = 0;
if(decode_nal(buf + buf_index, FFMIN(nalsize, NAL_PEEK_SIZE), partOfNal, &decodedNalSize, &nalType, &nal_ref_idc))
{
int pts = 0;
if(nalType == 1 || nalType == 2)
{
if(decode_slice_header(context, partOfNal, decodedNalSize, nal_ref_idc, nalType, pts_decoded, &slice_type, &pts))
{
ret = 1;
if(slice_type < lowestType)
lowestType = slice_type;
if(nal_ref_idc)
*skippable = 0;
if(pts_decoded == 0)
{
pts_decoded = 1;
if(pts > context->prevPts)
{
if(pts < context->prevPts)
lowestType = FF_B_TYPE;
context->prevPts = pts;
}
}
}
// Parser users assume I-frames are IDR-frames
// but in H.264 they don't have to be.
// Mark these as P-frames if they effectively are.
if (lowestType == FF_I_TYPE) lowestType = FF_P_TYPE;
}
else if(nalType == 5)
{
ret = 1;
#if 0 /*this was an attempt to figure out the PTS information and detect an out of order P frame before we hit its B frame */
context->prev_poc_lsb = 0;
context->poc_msb = 0;
context->prevPts = 0;
*precedesAPastFrame = 0;
#endif
*skippable = 0;
lowestType = FF_I_TYPE;
}
}
buf_index += nalsize;
}
if(lowestType != 20)
*type = lowestType;
return ret;
}
/*
* This function parses an h.264 bitstream, and assumes that it is given at least a full frame of data.
* @param parser A FFusionParserContext structure containg all our info
* @param buf The buffer to parse
* @param buf_size Size of the input buffer
* @param out_buf_size The number of bytes present in the first frame of data
* @param type The frame Type: FF_*_TYPE
* @param pts The PTS of the frame
* @return 1 if a frame is found, 0 otherwise
*/
static int parse_h264_stream(FFusionParserContext *parser, const uint8_t *buf, int buf_size, int *out_buf_size, int *type, int *skippable, int *skipped)
{
int endOfFrame;
int size = 0;
const uint8_t *parseBuf = buf;
int parseSize;
/*
* Somehow figure out of frame type
* For our use, a frame with any B slices is a B frame, and then a frame with any P slices is a P frame.
* An I frame has only I slices.
* I expect this involves a NAL decoder, and then look at the slice types.
* Nal is a f(1) always set to 0, u(2) of nal_ref_idc, and then u(5) of nal_unit_type.
* Nal types 1, 2 start a non-I frame, and type 5 starts an I frame. Each start with a slice header.
* Slice header has a ue(v) for first_mb_in_slice and then a ue(v) for the slice_type
* Slice types 0, 5 are P, 1, 6 are B, 2, 7 are I
*/
do
{
parseBuf = parseBuf + size;
parseSize = buf_size - size;
endOfFrame = (parser->parserStructure->avparse->split)(parser->avctx, parseBuf, parseSize);
if(endOfFrame == 0)
size = buf_size;
else
{
size += endOfFrame;
parseSize = endOfFrame;
}
}while(decode_nals(parser->internalContext, parseBuf, parseSize, type, skippable) == 0 && size < buf_size);
*skipped = 0;
*out_buf_size = size;
return 1;
}
static int init_h264_parser(FFusionParserContext *parser)
{
H264ParserContext *context = parser->internalContext;
context->nal_length_size = 2;
context->is_avc = 0;
return 1;
}
static int parse_extra_data_h264(FFusionParserContext *parser, const uint8_t *buf, int buf_size)
{
H264ParserContext *context = parser->internalContext;
const uint8_t *cur = buf;
int count, i, type, ref;
context->is_avc = 1;
count = *(cur+5) & 0x1f;
cur += 6;
for (i=0; i<count; i++)
{
int size = AV_RB16(cur);
int out_size = 0;
uint8_t *decoded = av_mallocz(size+FF_INPUT_BUFFER_PADDING_SIZE);
if(decode_nal(cur + 2, size, decoded, &out_size, &type, &ref))
decode_sps(context, decoded, out_size);
cur += size + 2;
free(decoded);
}
count = *(cur++);
for (i=0; i<count; i++)
{
int size = AV_RB16(cur);
int out_size = 0;
uint8_t *decoded = av_mallocz(size+FF_INPUT_BUFFER_PADDING_SIZE);
if(decode_nal(cur + 2, size, decoded, &out_size, &type, &ref))
decode_pps(context, decoded, out_size);
cur += size + 2;
free(decoded);
}
context->nal_length_size = ((*(buf+4)) & 0x03) + 1;
return 1;
}
extern AVCodecParser h264_parser;
static FFusionParser ffusionH264Parser = {
&h264_parser,
sizeof(H264ParserContext),
init_h264_parser,
parse_extra_data_h264,
parse_h264_stream,
};
static FFusionParser *ffusionFirstParser = NULL;
void registerFFusionParsers(FFusionParser *parser)
{
parser->next = ffusionFirstParser;
ffusionFirstParser = parser;
}
void initFFusionParsers()
{
static Boolean inited = FALSE;
int unlock = PerianInitEnter(&inited);
if(!inited)
{
inited = TRUE;
registerFFusionParsers(&ffusionMpeg4VideoParser);
registerFFusionParsers(&ffusionH264Parser);
registerFFusionParsers(&ffusionMpeg12VideoParser);
}
PerianInitExit(unlock);
}
void ffusionParserFree(FFusionParserContext *parser)
{
AVCodecParser *avparse = parser->parserStructure->avparse;
if(parser->pc)
{
if (avparse->parser_close)
avparse->parser_close(parser->pc);
av_free(parser->pc->priv_data);
av_free(parser->pc);
}
av_free(parser->avctx);
av_free(parser->internalContext);
free(parser);
}
FFusionParserContext *ffusionParserInit(int codec_id)
{
AVCodecParserContext *s;
AVCodecParser *parser;
FFusionParser *ffParser;
int ret, i;
if(codec_id == CODEC_ID_NONE)
return NULL;
if (!ffusionFirstParser) initFFusionParsers();
for(ffParser = ffusionFirstParser; ffParser != NULL; ffParser = ffParser->next) {
parser = ffParser->avparse;
for (i = 0; i < 5; i++)
if (parser->codec_ids[i] == codec_id)
goto found;
}
return NULL;
found:
s = av_mallocz(sizeof(AVCodecParserContext));
if (!s)
return NULL;
s->parser = parser;
s->priv_data = av_mallocz(parser->priv_data_size);
if (!s->priv_data) {
av_free(s);
return NULL;
}
if (parser->parser_init) {
ret = parser->parser_init(s);
if (ret != 0) {
av_free(s->priv_data);
av_free(s);
return NULL;
}
}
s->fetch_timestamp=1;
s->flags |= PARSER_FLAG_COMPLETE_FRAMES;
FFusionParserContext *parserContext = malloc(sizeof(FFusionParserContext));
parserContext->avctx = avcodec_alloc_context();
parserContext->pc = s;
parserContext->parserStructure = ffParser;
if(ffParser->internalContextSize)
parserContext->internalContext = av_mallocz(ffParser->internalContextSize);
else
parserContext->internalContext = NULL;
if(ffParser->init)
(ffParser->init)(parserContext);
return parserContext;
}
/*
* @param parser FFusionParserContext pointer
* @param buf The buffer to parse
* @param buf_size Size of the input buffer
* @return 1 if successful, 0 otherwise
*/
int ffusionParseExtraData(FFusionParserContext *parser, const uint8_t *buf, int buf_size)
{
if(parser->parserStructure->extra_data)
return (parser->parserStructure->extra_data)(parser, buf, buf_size);
return 1;
}
/*
* @param parser FFusionParserContext pointer
* @param buf The buffer to parse
* @param buf_size Size of the input buffer
* @param out_buf_size The number of bytes present in the first frame of data
* @param type The frame Type: FF_*_TYPE