jvdec.c
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1 /*
2  * Bitmap Brothers JV demuxer
3  * Copyright (c) 2005, 2011 Peter Ross <pross@xvid.org>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
28 #include "libavutil/intreadwrite.h"
29 #include "avformat.h"
30 #include "internal.h"
31 
32 #define JV_PREAMBLE_SIZE 5
33 
34 typedef struct {
35  int audio_size;
36  int video_size;
38  int video_type;
39 } JVFrame;
40 
41 typedef struct {
43  enum {
44  JV_AUDIO = 0,
46  JV_PADDING
47  } state;
48  int64_t pts;
50 
51 #define MAGIC " Compression by John M Phillips Copyright (C) 1995 The Bitmap Brothers Ltd."
52 
53 static int read_probe(AVProbeData *pd)
54 {
55  if (pd->buf[0] == 'J' && pd->buf[1] == 'V' &&
56  !memcmp(pd->buf + 4, MAGIC, FFMIN(strlen(MAGIC), pd->buf_size - 4)))
57  return AVPROBE_SCORE_MAX;
58  return 0;
59 }
60 
63 {
64  JVDemuxContext *jv = s->priv_data;
65  AVIOContext *pb = s->pb;
66  AVStream *vst, *ast;
67  int64_t audio_pts = 0;
68  int64_t offset;
69  int i;
70 
71  avio_skip(pb, 80);
72 
73  ast = avformat_new_stream(s, NULL);
74  vst = avformat_new_stream(s, NULL);
75  if (!ast || !vst)
76  return AVERROR(ENOMEM);
77 
79  vst->codec->codec_id = CODEC_ID_JV;
80  vst->codec->codec_tag = 0; /* no fourcc */
81  vst->codec->width = avio_rl16(pb);
82  vst->codec->height = avio_rl16(pb);
83  vst->nb_frames =
84  ast->nb_index_entries = avio_rl16(pb);
85  avpriv_set_pts_info(vst, 64, avio_rl16(pb), 1000);
86 
87  avio_skip(pb, 4);
88 
91  ast->codec->codec_tag = 0; /* no fourcc */
92  ast->codec->sample_rate = avio_rl16(pb);
93  ast->codec->channels = 1;
94  avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
95 
96  avio_skip(pb, 10);
97 
98  ast->index_entries = av_malloc(ast->nb_index_entries * sizeof(*ast->index_entries));
99  if (!ast->index_entries)
100  return AVERROR(ENOMEM);
101 
102  jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));
103  if (!jv->frames)
104  return AVERROR(ENOMEM);
105 
106  offset = 0x68 + ast->nb_index_entries * 16;
107  for(i = 0; i < ast->nb_index_entries; i++) {
108  AVIndexEntry *e = ast->index_entries + i;
109  JVFrame *jvf = jv->frames + i;
110 
111  /* total frame size including audio, video, palette data and padding */
112  e->size = avio_rl32(pb);
113  e->timestamp = i;
114  e->pos = offset;
115  offset += e->size;
116 
117  jvf->audio_size = avio_rl32(pb);
118  jvf->video_size = avio_rl32(pb);
119  jvf->palette_size = avio_r8(pb) ? 768 : 0;
120  jvf->video_size = FFMIN(FFMAX(jvf->video_size, 0),
121  INT_MAX - JV_PREAMBLE_SIZE - jvf->palette_size);
122  if (avio_r8(pb))
123  av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");
124  jvf->video_type = avio_r8(pb);
125  avio_skip(pb, 1);
126 
127  e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;
128  audio_pts += jvf->audio_size;
129 
130  e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;
131  }
132 
133  jv->state = JV_AUDIO;
134  return 0;
135 }
136 
138 {
139  JVDemuxContext *jv = s->priv_data;
140  AVIOContext *pb = s->pb;
141  AVStream *ast = s->streams[0];
142 
143  while (!s->pb->eof_reached && jv->pts < ast->nb_index_entries) {
144  const AVIndexEntry *e = ast->index_entries + jv->pts;
145  const JVFrame *jvf = jv->frames + jv->pts;
146 
147  switch(jv->state) {
148  case JV_AUDIO:
149  jv->state++;
150  if (jvf->audio_size ) {
151  if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)
152  return AVERROR(ENOMEM);
153  pkt->stream_index = 0;
154  pkt->pts = e->timestamp;
155  pkt->flags |= AV_PKT_FLAG_KEY;
156  return 0;
157  }
158  case JV_VIDEO:
159  jv->state++;
160  if (jvf->video_size || jvf->palette_size) {
161  int size = jvf->video_size + jvf->palette_size;
162  if (av_new_packet(pkt, size + JV_PREAMBLE_SIZE))
163  return AVERROR(ENOMEM);
164 
165  AV_WL32(pkt->data, jvf->video_size);
166  pkt->data[4] = jvf->video_type;
167  if (avio_read(pb, pkt->data + JV_PREAMBLE_SIZE, size) < 0)
168  return AVERROR(EIO);
169 
170  pkt->size = size + JV_PREAMBLE_SIZE;
171  pkt->stream_index = 1;
172  pkt->pts = jv->pts;
173  if (jvf->video_type != 1)
174  pkt->flags |= AV_PKT_FLAG_KEY;
175  return 0;
176  }
177  case JV_PADDING:
178  avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size
179  - jvf->palette_size, 0));
180  jv->state = JV_AUDIO;
181  jv->pts++;
182  }
183  }
184 
185  return AVERROR(EIO);
186 }
187 
188 static int read_seek(AVFormatContext *s, int stream_index,
189  int64_t ts, int flags)
190 {
191  JVDemuxContext *jv = s->priv_data;
192  AVStream *ast = s->streams[0];
193  int i;
194 
195  if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))
196  return AVERROR(ENOSYS);
197 
198  switch(stream_index) {
199  case 0:
200  i = av_index_search_timestamp(ast, ts, flags);
201  break;
202  case 1:
203  i = ts;
204  break;
205  default:
206  return 0;
207  }
208 
209  if (i < 0 || i >= ast->nb_index_entries)
210  return 0;
211 
212  jv->state = JV_AUDIO;
213  jv->pts = i;
214  avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET);
215  return 0;
216 }
217 
219  .name = "jv",
220  .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),
221  .priv_data_size = sizeof(JVDemuxContext),
225  .read_seek = read_seek,
226 };