FFmpeg
jvdec.c
Go to the documentation of this file.
1 /*
2  * Bitmap Brothers JV demuxer
3  * Copyright (c) 2005, 2011 Peter Ross <pross@xvid.org>
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  * Bitmap Brothers JV demuxer
25  * @author Peter Ross <pross@xvid.org>
26  */
27 
29 #include "libavutil/intreadwrite.h"
30 
31 #include "avformat.h"
32 #include "internal.h"
33 
34 #define JV_PREAMBLE_SIZE 5
35 
36 typedef struct JVFrame {
37  int audio_size; /**< audio packet size (bytes) */
38  int video_size; /**< video packet size (bytes) */
39  int palette_size; /**< palette size (bytes) */
40  int video_type; /**< per-frame video compression type */
41 } JVFrame;
42 
43 typedef struct JVDemuxContext {
45  enum {
46  JV_AUDIO = 0,
48  JV_PADDING
49  } state;
50  int64_t pts;
52 
53 #define MAGIC " Compression by John M Phillips Copyright (C) 1995 The Bitmap Brothers Ltd."
54 
55 static int read_probe(const AVProbeData *pd)
56 {
57  if (pd->buf[0] == 'J' && pd->buf[1] == 'V' && strlen(MAGIC) + 4 <= pd->buf_size &&
58  !memcmp(pd->buf + 4, MAGIC, strlen(MAGIC)))
59  return AVPROBE_SCORE_MAX;
60  return 0;
61 }
62 
64 {
65  JVDemuxContext *jv = s->priv_data;
66 
67  av_freep(&jv->frames);
68 
69  return 0;
70 }
71 
73 {
74  JVDemuxContext *jv = s->priv_data;
75  AVIOContext *pb = s->pb;
76  AVStream *vst, *ast;
77  int64_t audio_pts = 0;
78  int64_t offset;
79  int i;
80 
81  avio_skip(pb, 80);
82 
83  ast = avformat_new_stream(s, NULL);
84  vst = avformat_new_stream(s, NULL);
85  if (!ast || !vst)
86  return AVERROR(ENOMEM);
87 
90  vst->codecpar->codec_tag = 0; /* no fourcc */
91  vst->codecpar->width = avio_rl16(pb);
92  vst->codecpar->height = avio_rl16(pb);
93  vst->duration =
94  vst->nb_frames =
95  ast->nb_index_entries = avio_rl16(pb);
96  avpriv_set_pts_info(vst, 64, avio_rl16(pb), 1000);
97 
98  avio_skip(pb, 4);
99 
102  ast->codecpar->codec_tag = 0; /* no fourcc */
103  ast->codecpar->sample_rate = avio_rl16(pb);
104  ast->codecpar->channels = 1;
106  avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
107 
108  avio_skip(pb, 10);
109 
111  sizeof(*ast->index_entries));
112  if (!ast->index_entries)
113  return AVERROR(ENOMEM);
114 
115  jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));
116  if (!jv->frames)
117  return AVERROR(ENOMEM);
118 
119  offset = 0x68 + ast->nb_index_entries * 16;
120  for (i = 0; i < ast->nb_index_entries; i++) {
121  AVIndexEntry *e = ast->index_entries + i;
122  JVFrame *jvf = jv->frames + i;
123 
124  /* total frame size including audio, video, palette data and padding */
125  e->size = avio_rl32(pb);
126  e->timestamp = i;
127  e->pos = offset;
128  offset += e->size;
129 
130  jvf->audio_size = avio_rl32(pb);
131  jvf->video_size = avio_rl32(pb);
132  jvf->palette_size = avio_r8(pb) ? 768 : 0;
133 
134  if ((jvf->video_size | jvf->audio_size) & ~0xFFFFFF ||
135  e->size - jvf->audio_size
136  - jvf->video_size
137  - jvf->palette_size < 0) {
138  if (s->error_recognition & AV_EF_EXPLODE) {
139  read_close(s);
140  return AVERROR_INVALIDDATA;
141  }
142  jvf->audio_size =
143  jvf->video_size =
144  jvf->palette_size = 0;
145  }
146 
147  if (avio_r8(pb))
148  av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");
149 
150  jvf->video_type = avio_r8(pb);
151  avio_skip(pb, 1);
152 
153  e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;
154  audio_pts += jvf->audio_size;
155 
156  e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;
157  }
158 
159  jv->state = JV_AUDIO;
160  return 0;
161 }
162 
164 {
165  JVDemuxContext *jv = s->priv_data;
166  AVIOContext *pb = s->pb;
167  AVStream *ast = s->streams[0];
168 
169  while (!avio_feof(s->pb) && jv->pts < ast->nb_index_entries) {
170  const AVIndexEntry *e = ast->index_entries + jv->pts;
171  const JVFrame *jvf = jv->frames + jv->pts;
172 
173  switch (jv->state) {
174  case JV_AUDIO:
175  jv->state++;
176  if (jvf->audio_size) {
177  if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)
178  return AVERROR(ENOMEM);
179  pkt->stream_index = 0;
180  pkt->pts = e->timestamp;
181  pkt->flags |= AV_PKT_FLAG_KEY;
182  return 0;
183  }
184  case JV_VIDEO:
185  jv->state++;
186  if (jvf->video_size || jvf->palette_size) {
187  int ret;
188  int size = jvf->video_size + jvf->palette_size;
189  if (av_new_packet(pkt, size + JV_PREAMBLE_SIZE))
190  return AVERROR(ENOMEM);
191 
192  AV_WL32(pkt->data, jvf->video_size);
193  pkt->data[4] = jvf->video_type;
194  ret = avio_read(pb, pkt->data + JV_PREAMBLE_SIZE, size);
195  if (ret < 0)
196  return ret;
197  if (ret < size) {
198  memset(pkt->data + JV_PREAMBLE_SIZE + ret, 0,
200  pkt->flags |= AV_PKT_FLAG_CORRUPT;
201  }
202  pkt->size = ret + JV_PREAMBLE_SIZE;
203  pkt->stream_index = 1;
204  pkt->pts = jv->pts;
205  if (jvf->video_type != 1)
206  pkt->flags |= AV_PKT_FLAG_KEY;
207  return 0;
208  }
209  case JV_PADDING:
210  avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size
211  - jvf->palette_size, 0));
212  jv->state = JV_AUDIO;
213  jv->pts++;
214  }
215  }
216 
217  if (s->pb->eof_reached)
218  return AVERROR_EOF;
219 
220  return AVERROR(EIO);
221 }
222 
223 static int read_seek(AVFormatContext *s, int stream_index,
224  int64_t ts, int flags)
225 {
226  JVDemuxContext *jv = s->priv_data;
227  AVStream *ast = s->streams[0];
228  int i;
229 
230  if (flags & (AVSEEK_FLAG_BYTE | AVSEEK_FLAG_FRAME))
231  return AVERROR(ENOSYS);
232 
233  switch (stream_index) {
234  case 0:
235  i = av_index_search_timestamp(ast, ts, flags);
236  break;
237  case 1:
238  i = ts;
239  break;
240  default:
241  return 0;
242  }
243 
244  if (i < 0 || i >= ast->nb_index_entries)
245  return 0;
246  if (avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET) < 0)
247  return -1;
248 
249  jv->state = JV_AUDIO;
250  jv->pts = i;
251  return 0;
252 }
253 
255  .name = "jv",
256  .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),
257  .priv_data_size = sizeof(JVDemuxContext),
261  .read_seek = read_seek,
263 };
int video_type
per-frame video compression type
Definition: jvdec.c:40
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t pts
Definition: jvdec.c:50
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4892
int64_t pos
Definition: avformat.h:810
Definition: jvdec.c:36
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3957
int size
Definition: avcodec.h:1478
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1110
JVFrame * frames
Definition: jvdec.c:44
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
static AVPacket pkt
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: jvdec.c:163
static struct @315 state
Format I/O context.
Definition: avformat.h:1358
#define MAGIC
Definition: jvdec.c:53
#define av_malloc(s)
int width
Video only.
Definition: avcodec.h:4023
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf offset
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4465
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
#define JV_PREAMBLE_SIZE
Definition: jvdec.c:34
uint8_t * data
Definition: avcodec.h:1477
#define AVERROR_EOF
End of file.
Definition: error.h:55
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:310
ptrdiff_t size
Definition: opengl_enc.c:100
static int read_seek(AVFormatContext *s, int stream_index, int64_t ts, int flags)
Definition: jvdec.c:223
uint64_t channel_layout
Audio only.
Definition: avcodec.h:4059
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:650
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1509
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
#define AVINDEX_KEYFRAME
Definition: avformat.h:817
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2154
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:772
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:811
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3953
#define FFMAX(a, b)
Definition: common.h:94
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1483
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:641
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:449
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
audio channel layout utility functions
#define s(width, name)
Definition: cbs_vp9.c:257
#define AV_EF_EXPLODE
abort decoding on minor error detection
Definition: avcodec.h:2705
int palette_size
palette size (bytes)
Definition: jvdec.c:39
static int read_close(AVFormatContext *s)
Definition: jvdec.c:63
Stream structure.
Definition: avformat.h:881
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
int nb_index_entries
Definition: avformat.h:1112
#define AVSEEK_FLAG_BYTE
seeking based on position in bytes
Definition: avformat.h:2512
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
#define flags(name, subs,...)
Definition: cbs_av1.c:561
static int read_probe(const AVProbeData *pd)
Definition: jvdec.c:55
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:930
int sample_rate
Audio only.
Definition: avcodec.h:4067
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:756
Main libavformat public API header.
int video_size
video packet size (bytes)
Definition: jvdec.c:38
int error_recognition
Error recognition; higher values will detect more errors but may misdetect some more or less valid pa...
Definition: avformat.h:1625
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:932
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: avcodec.h:1510
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:790
int eof_reached
true if was unable to read due to error or eof
Definition: avio.h:239
void * priv_data
Format private data.
Definition: avformat.h:1386
#define AVSEEK_FLAG_FRAME
seeking based on frame number
Definition: avformat.h:2514
int channels
Audio only.
Definition: avcodec.h:4063
#define av_freep(p)
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3961
int stream_index
Definition: avcodec.h:1479
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:1454
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1470
enum JVDemuxContext::@265 state
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
int audio_size
audio packet size (bytes)
Definition: jvdec.c:37
#define AV_WL32(p, v)
Definition: intreadwrite.h:426
AVInputFormat ff_jv_demuxer
Definition: jvdec.c:254
static int read_header(AVFormatContext *s)
Definition: jvdec.c:72