FFmpeg
mjpega_dump_header_bsf.c
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1 /*
2  * MJPEG A dump header bitstream filter
3  * Copyright (c) 2006 Baptiste Coudurier
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * MJPEG A dump header bitstream filter
25  * modifies bitstream to be decoded by quicktime
26  */
27 
28 #include "bsf.h"
29 #include "bsf_internal.h"
30 #include "bytestream.h"
31 #include "mjpeg.h"
32 
33 
35 {
36  AVPacket *in;
37  uint8_t *out_buf;
38  unsigned dqt = 0, dht = 0, sof0 = 0;
39  int ret = 0, i;
40 
41  ret = ff_bsf_get_packet(ctx, &in);
42  if (ret < 0)
43  return ret;
44 
45  ret = av_new_packet(out, in->size + 44);
46  if (ret < 0)
47  goto fail;
48 
50  if (ret < 0)
51  goto fail;
52 
53  out_buf = out->data;
54  bytestream_put_byte(&out_buf, 0xff);
55  bytestream_put_byte(&out_buf, SOI);
56  bytestream_put_byte(&out_buf, 0xff);
57  bytestream_put_byte(&out_buf, APP1);
58  bytestream_put_be16(&out_buf, 42); /* size */
59  bytestream_put_be32(&out_buf, 0);
60  bytestream_put_buffer(&out_buf, "mjpg", 4);
61  bytestream_put_be32(&out_buf, in->size + 44); /* field size */
62  bytestream_put_be32(&out_buf, in->size + 44); /* pad field size */
63  bytestream_put_be32(&out_buf, 0); /* next ptr */
64 
65  for (i = 0; i < in->size - 1; i++) {
66  if (in->data[i] == 0xff) {
67  switch (in->data[i + 1]) {
68  case DQT: dqt = i + 46; break;
69  case DHT: dht = i + 46; break;
70  case SOF0: sof0 = i + 46; break;
71  case SOS:
72  bytestream_put_be32(&out_buf, dqt); /* quant off */
73  bytestream_put_be32(&out_buf, dht); /* huff off */
74  bytestream_put_be32(&out_buf, sof0); /* image off */
75  bytestream_put_be32(&out_buf, i + 46); /* scan off */
76  bytestream_put_be32(&out_buf, i + 46 + AV_RB16(in->data + i + 2)); /* data off */
77  bytestream_put_buffer(&out_buf, in->data + 2, in->size - 2); /* skip already written SOI */
78 
79  out->size = out_buf - out->data;
80  av_packet_free(&in);
81  return 0;
82  case APP1:
83  if (i + 8 < in->size && AV_RL32(in->data + i + 8) == AV_RL32("mjpg")) {
84  av_log(ctx, AV_LOG_ERROR, "bitstream already formatted\n");
87  av_packet_free(&in);
88  return 0;
89  }
90  }
91  }
92  }
93  av_log(ctx, AV_LOG_ERROR, "could not find SOS marker in bitstream\n");
94 fail:
96  av_packet_free(&in);
97  return AVERROR_INVALIDDATA;
98 }
99 
100 static const enum AVCodecID codec_ids[] = {
102 };
103 
105  .name = "mjpegadump",
106  .filter = mjpega_dump_header,
107  .codec_ids = codec_ids,
108 };
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:417
mjpeg.h
bsf_internal.h
out
FILE * out
Definition: movenc.c:54
SOS
@ SOS
Definition: mjpeg.h:72
APP1
@ APP1
Definition: mjpeg.h:80
SOF0
@ SOF0
Definition: mjpeg.h:39
AVBitStreamFilter::name
const char * name
Definition: bsf.h:91
AVPacket::data
uint8_t * data
Definition: packet.h:373
ff_bsf_get_packet
int ff_bsf_get_packet(AVBSFContext *ctx, AVPacket **pkt)
Called by the bitstream filters to get the next packet for filtering.
Definition: bsf.c:231
av_packet_free
void av_packet_free(AVPacket **pkt)
Free the packet, if the packet is reference counted, it will be unreferenced first.
Definition: avpacket.c:75
AVBSFContext
The bitstream filter state.
Definition: bsf.h:47
bsf.h
fail
#define fail()
Definition: checkasm.h:127
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:99
ctx
AVFormatContext * ctx
Definition: movenc.c:48
av_packet_move_ref
void av_packet_move_ref(AVPacket *dst, AVPacket *src)
Move every field in src to dst and reset src.
Definition: avpacket.c:474
mjpega_dump_header
static int mjpega_dump_header(AVBSFContext *ctx, AVPacket *out)
Definition: mjpega_dump_header_bsf.c:34
AVCodecID
AVCodecID
Identify the syntax and semantics of the bitstream.
Definition: codec_id.h:47
AVPacket::size
int size
Definition: packet.h:374
DQT
@ DQT
Definition: mjpeg.h:73
AV_CODEC_ID_MJPEG
@ AV_CODEC_ID_MJPEG
Definition: codec_id.h:57
bytestream_put_buffer
static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
Definition: bytestream.h:372
av_packet_copy_props
int av_packet_copy_props(AVPacket *dst, const AVPacket *src)
Copy only "properties" fields from src to dst.
Definition: avpacket.c:380
i
int i
Definition: input.c:406
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:48
DHT
@ DHT
Definition: mjpeg.h:56
ret
ret
Definition: filter_design.txt:187
dht
static int FUNC() dht(CodedBitstreamContext *ctx, RWContext *rw, JPEGRawHuffmanTableSpecification *current)
Definition: cbs_jpeg_syntax_template.c:102
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
ff_mjpega_dump_header_bsf
const AVBitStreamFilter ff_mjpega_dump_header_bsf
Definition: mjpega_dump_header_bsf.c:104
AVBitStreamFilter
Definition: bsf.h:90
dqt
static int FUNC() dqt(CodedBitstreamContext *ctx, RWContext *rw, JPEGRawQuantisationTableSpecification *current)
Definition: cbs_jpeg_syntax_template.c:62
SOI
@ SOI
Definition: mjpeg.h:70
AVPacket
This structure stores compressed data.
Definition: packet.h:350
bytestream.h
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
codec_ids
static enum AVCodecID codec_ids[]
Definition: mjpega_dump_header_bsf.c:100
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98