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smjpegenc.c
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1 /*
2  * SMJPEG muxer
3  * Copyright (c) 2012 Paul B Mahol
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  * This is a muxer for Loki SDL Motion JPEG files
25  */
26 
27 #include "avformat.h"
28 #include "internal.h"
29 #include "smjpeg.h"
30 
31 typedef struct SMJPEGMuxContext {
32  uint32_t duration;
34 
36 {
38  AVIOContext *pb = s->pb;
39  int n, tag;
40 
41  if (s->nb_streams > 2) {
42  av_log(s, AV_LOG_ERROR, "more than >2 streams are not supported\n");
43  return AVERROR(EINVAL);
44  }
45  avio_write(pb, SMJPEG_MAGIC, 8);
46  avio_wb32(pb, 0);
47  avio_wb32(pb, 0);
48 
49  while ((t = av_dict_get(s->metadata, "", t, AV_DICT_IGNORE_SUFFIX))) {
50  avio_wl32(pb, SMJPEG_TXT);
51  avio_wb32(pb, strlen(t->key) + strlen(t->value) + 3);
52  avio_write(pb, t->key, strlen(t->key));
53  avio_write(pb, " = ", 3);
54  avio_write(pb, t->value, strlen(t->value));
55  }
56 
57  for (n = 0; n < s->nb_streams; n++) {
58  AVStream *st = s->streams[n];
59  AVCodecContext *codec = st->codec;
60  if (codec->codec_type == AVMEDIA_TYPE_AUDIO) {
62  if (!tag) {
63  av_log(s, AV_LOG_ERROR, "unsupported audio codec\n");
64  return AVERROR(EINVAL);
65  }
66  avio_wl32(pb, SMJPEG_SND);
67  avio_wb32(pb, 8);
68  avio_wb16(pb, codec->sample_rate);
69  avio_w8(pb, codec->bits_per_coded_sample);
70  avio_w8(pb, codec->channels);
71  avio_wl32(pb, tag);
72  avpriv_set_pts_info(st, 32, 1, 1000);
73  } else if (codec->codec_type == AVMEDIA_TYPE_VIDEO) {
75  if (!tag) {
76  av_log(s, AV_LOG_ERROR, "unsupported video codec\n");
77  return AVERROR(EINVAL);
78  }
79  avio_wl32(pb, SMJPEG_VID);
80  avio_wb32(pb, 12);
81  avio_wb32(pb, 0);
82  avio_wb16(pb, codec->width);
83  avio_wb16(pb, codec->height);
84  avio_wl32(pb, tag);
85  avpriv_set_pts_info(st, 32, 1, 1000);
86  }
87  }
88 
90  avio_flush(pb);
91 
92  return 0;
93 }
94 
96 {
97  SMJPEGMuxContext *smc = s->priv_data;
98  AVIOContext *pb = s->pb;
99  AVStream *st = s->streams[pkt->stream_index];
100  AVCodecContext *codec = st->codec;
101 
102  if (codec->codec_type == AVMEDIA_TYPE_AUDIO)
103  avio_wl32(pb, SMJPEG_SNDD);
104  else if (codec->codec_type == AVMEDIA_TYPE_VIDEO)
105  avio_wl32(pb, SMJPEG_VIDD);
106  else
107  return 0;
108 
109  avio_wb32(pb, pkt->pts);
110  avio_wb32(pb, pkt->size);
111  avio_write(pb, pkt->data, pkt->size);
112 
113  smc->duration = FFMAX(smc->duration, pkt->pts + pkt->duration);
114  return 0;
115 }
116 
118 {
119  SMJPEGMuxContext *smc = s->priv_data;
120  AVIOContext *pb = s->pb;
121  int64_t currentpos;
122 
123  if (pb->seekable) {
124  currentpos = avio_tell(pb);
125  avio_seek(pb, 12, SEEK_SET);
126  avio_wb32(pb, smc->duration);
127  avio_seek(pb, currentpos, SEEK_SET);
128  }
129 
130  avio_wl32(pb, SMJPEG_DONE);
131 
132  return 0;
133 }
134 
136  .name = "smjpeg",
137  .long_name = NULL_IF_CONFIG_SMALL("Loki SDL MJPEG"),
138  .priv_data_size = sizeof(SMJPEGMuxContext),
139  .audio_codec = AV_CODEC_ID_PCM_S16LE,
140  .video_codec = AV_CODEC_ID_MJPEG,
145  .codec_tag = (const AVCodecTag *const []){ ff_codec_smjpeg_video_tags, ff_codec_smjpeg_audio_tags, 0 },
146 };