Files
ffmpeg-patched/libavcodec/mjpeg_parser.c
T
gx dcecd42de4 FFmpeg 7.1 + cuframes input demuxer
Snapshot FFmpeg n7.1 (release tag) с применённым patch'ем для cuframes
input format. Используется как FFMPEG_REPO_OVERRIDE в NickM-27/FFmpeg-Builds
fork для статической сборки patched binary под Frigate (Debian 12 / glibc 2.36).

Apply changes:
  + libavformat/cuframesdec.c (новый — реализация демуксера)
  M libavformat/Makefile (CONFIG_CUFRAMES_DEMUXER target)
  M libavformat/allformats.c (extern declaration)
  M configure (--enable-libcuframes option + dep check)

Patch source: https://git.goldix.org/gx/cuframes (filter/ffmpeg-7.1-cuframes-demuxer.patch)

History сброшена (snapshot вместо fork) потому что upstream shallow clone
не позволял push в gitea. Полная история FFmpeg — на github.com/FFmpeg/FFmpeg n7.1.
2026-05-17 11:43:10 +01:00

137 lines
3.9 KiB
C

/*
* MJPEG parser
* Copyright (c) 2000, 2001 Fabrice Bellard
* Copyright (c) 2003 Alex Beregszaszi
* Copyright (c) 2003-2004 Michael Niedermayer
*
* 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
*/
/**
* @file
* MJPEG parser.
*/
#include "parser.h"
typedef struct MJPEGParserContext{
ParseContext pc;
int size;
}MJPEGParserContext;
/**
* Find the end of the current frame in the bitstream.
* @return the position of the first byte of the next frame, or -1
*/
static int find_frame_end(MJPEGParserContext *m, const uint8_t *buf, int buf_size){
ParseContext *pc= &m->pc;
int vop_found, i;
uint32_t state;
vop_found= pc->frame_start_found;
state= pc->state;
i=0;
if(!vop_found){
for(i=0; i<buf_size;){
state= (state<<8) | buf[i];
if(state>=0xFFC00000 && state<=0xFFFEFFFF){
if(state>=0xFFD8FFC0 && state<=0xFFD8FFFF){
i++;
vop_found=1;
break;
}else if(state<0xFFD00000 || state>0xFFD9FFFF){
m->size= (state&0xFFFF)-1;
}
}
if(m->size>0){
int size= FFMIN(buf_size-i, m->size);
i+=size;
m->size-=size;
state=0;
continue;
}else
i++;
}
}
if(vop_found){
/* EOF considered as end of frame */
if (buf_size == 0)
return 0;
for(; i<buf_size;){
state= (state<<8) | buf[i];
if(state>=0xFFC00000 && state<=0xFFFEFFFF){
if(state>=0xFFD8FFC0 && state<=0xFFD8FFFF){
pc->frame_start_found=0;
pc->state=0;
return i-3;
} else if((state>>16)==0xFFD9 && (state&0xFFFF)!=0xFFD8){
state= 0xFFD900|(state&0xFF);
} else if(state<0xFFD00000 || state>0xFFD9FFFF){
m->size= (state&0xFFFF)-1;
}
}
if(m->size>0){
int size= FFMIN(buf_size-i, m->size);
i+=size;
m->size-=size;
state=0;
continue;
}else
i++;
}
}
pc->frame_start_found= vop_found;
pc->state= state;
return END_NOT_FOUND;
}
static int jpeg_parse(AVCodecParserContext *s,
AVCodecContext *avctx,
const uint8_t **poutbuf, int *poutbuf_size,
const uint8_t *buf, int buf_size)
{
MJPEGParserContext *m = s->priv_data;
ParseContext *pc = &m->pc;
int next;
if(s->flags & PARSER_FLAG_COMPLETE_FRAMES){
next= buf_size;
}else{
next= find_frame_end(m, buf, buf_size);
if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
*poutbuf = NULL;
*poutbuf_size = 0;
return buf_size;
}
}
*poutbuf = buf;
*poutbuf_size = buf_size;
return next;
}
const AVCodecParser ff_mjpeg_parser = {
.codec_ids = { AV_CODEC_ID_MJPEG, AV_CODEC_ID_JPEGLS },
.priv_data_size = sizeof(MJPEGParserContext),
.parser_parse = jpeg_parse,
.parser_close = ff_parse_close,
};