FFmpeg: libavformat/rl2.c Source File

FFmpeg
rl2.c
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1 /*
2  * RL2 Format Demuxer
3  * Copyright (c) 2008 Sascha Sommer (saschasommer@freenet.de)
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  * RL2 file demuxer
24  * @file
25  * @author Sascha Sommer (saschasommer@freenet.de)
26  * @see http://wiki.multimedia.cx/index.php?title=RL2
27  *
28  * extradata:
29  * 2 byte le initial drawing offset within 320x200 viewport
30  * 4 byte le number of used colors
31  * 256 * 3 bytes rgb palette
32  * optional background_frame
33  */
34 
35 #include <stdint.h>
36 
37 #include "libavutil/intreadwrite.h"
38 #include "libavutil/mathematics.h"
39 #include "avformat.h"
40 #include "internal.h"
41 
42  #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
43 
44  #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
45  #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
46  #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
47 
48  typedef struct Rl2DemuxContext {
49   unsigned int index_pos[2]; ///< indexes in the sample tables
50 } Rl2DemuxContext;
51 
52 
53 /**
54  * check if the file is in rl2 format
55  * @param p probe buffer
56  * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
57  */
58  static int rl2_probe(AVProbeData *p)
59 {
60 
61  if(AV_RB32(&p->buf[0]) != FORM_TAG)
62  return 0;
63 
64  if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
65  AV_RB32(&p->buf[8]) != RLV3_TAG)
66  return 0;
67 
68  return AVPROBE_SCORE_MAX;
69 }
70 
71 /**
72  * read rl2 header data and setup the avstreams
73  * @param s demuxer context
74  * @return 0 on success, AVERROR otherwise
75  */
76  static av_cold int rl2_read_header(AVFormatContext *s)
77 {
78  AVIOContext *pb = s->pb;
79  AVStream *st;
80  unsigned int frame_count;
81  unsigned int audio_frame_counter = 0;
82  unsigned int video_frame_counter = 0;
83  unsigned int back_size;
84  unsigned short sound_rate;
85  unsigned short rate;
86  unsigned short channels;
87  unsigned short def_sound_size;
88  unsigned int signature;
89  unsigned int pts_den = 11025; /* video only case */
90  unsigned int pts_num = 1103;
91  unsigned int* chunk_offset = NULL;
92  int* chunk_size = NULL;
93  int* audio_size = NULL;
94  int i;
95  int ret = 0;
96 
97  avio_skip(pb,4); /* skip FORM tag */
98  back_size = avio_rl32(pb); /**< get size of the background frame */
99  signature = avio_rb32(pb);
100  avio_skip(pb, 4); /* data size */
101  frame_count = avio_rl32(pb);
102 
103  /* disallow back_sizes and frame_counts that may lead to overflows later */
104  if(back_size > INT_MAX/2 || frame_count > INT_MAX / sizeof(uint32_t))
105  return AVERROR_INVALIDDATA;
106 
107  avio_skip(pb, 2); /* encoding method */
108  sound_rate = avio_rl16(pb);
109  rate = avio_rl16(pb);
110  channels = avio_rl16(pb);
111  def_sound_size = avio_rl16(pb);
112 
113  /** setup video stream */
114  st = avformat_new_stream(s, NULL);
115  if(!st)
116  return AVERROR(ENOMEM);
117 
118  st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
119  st->codecpar->codec_id = AV_CODEC_ID_RL2;
120  st->codecpar->codec_tag = 0; /* no fourcc */
121  st->codecpar->width = 320;
122  st->codecpar->height = 200;
123 
124  /** allocate and fill extradata */
125  st->codecpar->extradata_size = EXTRADATA1_SIZE;
126 
127  if(signature == RLV3_TAG && back_size > 0)
128  st->codecpar->extradata_size += back_size;
129 
130  if(ff_get_extradata(s, st->codecpar, pb, st->codecpar->extradata_size) < 0)
131  return AVERROR(ENOMEM);
132 
133  /** setup audio stream if present */
134  if(sound_rate){
135  if (!channels || channels > 42) {
136  av_log(s, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);
137  return AVERROR_INVALIDDATA;
138  }
139 
140  pts_num = def_sound_size;
141  pts_den = rate;
142 
143  st = avformat_new_stream(s, NULL);
144  if (!st)
145  return AVERROR(ENOMEM);
146  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
147  st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
148  st->codecpar->codec_tag = 1;
149  st->codecpar->channels = channels;
150  st->codecpar->bits_per_coded_sample = 8;
151  st->codecpar->sample_rate = rate;
152  st->codecpar->bit_rate = st->codecpar->channels * st->codecpar->sample_rate *
153  st->codecpar->bits_per_coded_sample;
154  st->codecpar->block_align = st->codecpar->channels *
155  st->codecpar->bits_per_coded_sample / 8;
156  avpriv_set_pts_info(st,32,1,rate);
157  }
158 
159  avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
160 
161  chunk_size = av_malloc(frame_count * sizeof(uint32_t));
162  audio_size = av_malloc(frame_count * sizeof(uint32_t));
163  chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
164 
165  if(!chunk_size || !audio_size || !chunk_offset){
166  av_free(chunk_size);
167  av_free(audio_size);
168  av_free(chunk_offset);
169  return AVERROR(ENOMEM);
170  }
171 
172  /** read offset and size tables */
173  for(i=0; i < frame_count;i++) {
174  if (avio_feof(pb))
175  return AVERROR_INVALIDDATA;
176  chunk_size[i] = avio_rl32(pb);
177  }
178  for(i=0; i < frame_count;i++) {
179  if (avio_feof(pb))
180  return AVERROR_INVALIDDATA;
181  chunk_offset[i] = avio_rl32(pb);
182  }
183  for(i=0; i < frame_count;i++) {
184  if (avio_feof(pb))
185  return AVERROR_INVALIDDATA;
186  audio_size[i] = avio_rl32(pb) & 0xFFFF;
187  }
188 
189  /** build the sample index */
190  for(i=0;i<frame_count;i++){
191  if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
192  ret = AVERROR_INVALIDDATA;
193  break;
194  }
195 
196  if(sound_rate && audio_size[i]){
197  av_add_index_entry(s->streams[1], chunk_offset[i],
198  audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
199  audio_frame_counter += audio_size[i] / channels;
200  }
201  av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
202  video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
203  ++video_frame_counter;
204  }
205 
206 
207  av_free(chunk_size);
208  av_free(audio_size);
209  av_free(chunk_offset);
210 
211  return ret;
212 }
213 
214 /**
215  * read a single audio or video packet
216  * @param s demuxer context
217  * @param pkt the packet to be filled
218  * @return 0 on success, AVERROR otherwise
219  */
220  static int rl2_read_packet(AVFormatContext *s,
221  AVPacket *pkt)
222 {
223  Rl2DemuxContext *rl2 = s->priv_data;
224  AVIOContext *pb = s->pb;
225  AVIndexEntry *sample = NULL;
226  int i;
227  int ret = 0;
228  int stream_id = -1;
229  int64_t pos = INT64_MAX;
230 
231  /** check if there is a valid video or audio entry that can be used */
232  for(i=0; i<s->nb_streams; i++){
233  if(rl2->index_pos[i] < s->streams[i]->nb_index_entries
234  && s->streams[i]->index_entries[ rl2->index_pos[i] ].pos < pos){
235  sample = &s->streams[i]->index_entries[ rl2->index_pos[i] ];
236  pos= sample->pos;
237  stream_id= i;
238  }
239  }
240 
241  if(stream_id == -1)
242  return AVERROR_EOF;
243 
244  ++rl2->index_pos[stream_id];
245 
246  /** position the stream (will probably be there anyway) */
247  avio_seek(pb, sample->pos, SEEK_SET);
248 
249  /** fill the packet */
250  ret = av_get_packet(pb, pkt, sample->size);
251  if(ret != sample->size){
252  av_packet_unref(pkt);
253  return AVERROR(EIO);
254  }
255 
256  pkt->stream_index = stream_id;
257  pkt->pts = sample->timestamp;
258 
259  return ret;
260 }
261 
262 /**
263  * seek to a new timestamp
264  * @param s demuxer context
265  * @param stream_index index of the stream that should be seeked
266  * @param timestamp wanted timestamp
267  * @param flags direction and seeking mode
268  * @return 0 on success, -1 otherwise
269  */
270  static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
271 {
272  AVStream *st = s->streams[stream_index];
273  Rl2DemuxContext *rl2 = s->priv_data;
274  int i;
275  int index = av_index_search_timestamp(st, timestamp, flags);
276  if(index < 0)
277  return -1;
278 
279  rl2->index_pos[stream_index] = index;
280  timestamp = st->index_entries[index].timestamp;
281 
282  for(i=0; i < s->nb_streams; i++){
283  AVStream *st2 = s->streams[i];
284  index = av_index_search_timestamp(st2,
285  av_rescale_q(timestamp, st->time_base, st2->time_base),
286  flags | AVSEEK_FLAG_BACKWARD);
287 
288  if(index < 0)
289  index = 0;
290 
291  rl2->index_pos[i] = index;
292  }
293 
294  return 0;
295 }
296 
297  AVInputFormat ff_rl2_demuxer = {
298  .name = "rl2",
299  .long_name = NULL_IF_CONFIG_SMALL("RL2"),
300  .priv_data_size = sizeof(Rl2DemuxContext),
301  .read_probe = rl2_probe,
302  .read_header = rl2_read_header,
303  .read_packet = rl2_read_packet,
304  .read_seek = rl2_read_seek,
305 };
AVSEEK_FLAG_BACKWARD
#define AVSEEK_FLAG_BACKWARD
Definition: avformat.h:2486
NULL
#define NULL
Definition: coverity.c:32
s
const char * s
Definition: avisynth_c.h:768
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
av_add_index_entry
int av_add_index_entry(AVStream *st, int64_t pos, int64_t timestamp, int size, int distance, int flags)
Add an index entry into a sorted list.
Definition: utils.c:2038
avpriv_set_pts_info
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:4820
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:803
rl2_read_seek
static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
seek to a new timestamp
Definition: rl2.c:270
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:153
channels
channels
Definition: aptx.c:30
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3884
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
AVStream::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: avformat.h:1102
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
AVIndexEntry::size
int size
Definition: avformat.h:815
sample
#define sample
Definition: flacdsp_template.c:44
ff_rl2_demuxer
AVInputFormat ff_rl2_demuxer
Definition: rl2.c:297
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
signature
static const char signature[]
Definition: ipmovie.c:615
av_cold
#define av_cold
Definition: attributes.h:82
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
AVCodecParameters::width
int width
Video only.
Definition: avcodec.h:3950
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:801
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4450
AV_RB32
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_RB32
Definition: bytestream.h:87
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1410
flags
static int flags
Definition: log.c:55
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
av_get_packet
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
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: avcodec.h:3913
av_rescale_q
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:810
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: utils.c:2147
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:770
AVERROR
#define AVERROR(e)
Definition: error.h:43
AV_CODEC_ID_RL2
Definition: avcodec.h:332
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:804
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3880
AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVCodecParameters::extradata_size
int extradata_size
Size of the extradata content in bytes.
Definition: avcodec.h:3902
rl2_probe
static int rl2_probe(AVProbeData *p)
check if the file is in rl2 format
Definition: rl2.c:58
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1398
AVCodecParameters::block_align
int block_align
Audio only.
Definition: avcodec.h:4001
read_probe
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
AVStream
Stream structure.
Definition: avformat.h:873
AV_CODEC_ID_PCM_U8
Definition: avcodec.h:457
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
FORM_TAG
#define FORM_TAG
Definition: rl2.c:44
rl2_read_packet
static int rl2_read_packet(AVFormatContext *s, AVPacket *pkt)
read a single audio or video packet
Definition: rl2.c:220
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:592
RLV2_TAG
#define RLV2_TAG
Definition: rl2.c:45
AVStream::nb_index_entries
int nb_index_entries
Definition: avformat.h:1104
index
int index
Definition: gxfenc.c:89
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
RLV3_TAG
#define RLV3_TAG
Definition: rl2.c:46
EXTRADATA1_SIZE
#define EXTRADATA1_SIZE
video base, clr, palette
Definition: rl2.c:42
rl2_read_header
static av_cold int rl2_read_header(AVFormatContext *s)
read rl2 header data and setup the avstreams
Definition: rl2.c:76
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: avcodec.h:3994
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:460
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:754
avformat.h
Main libavformat public API header.
ff_get_extradata
int ff_get_extradata(AVFormatContext *s, AVCodecParameters *par, AVIOContext *pb, int size)
Allocate extradata with additional AV_INPUT_BUFFER_PADDING_SIZE at end which is always set to 0 and f...
Definition: utils.c:3298
Rl2DemuxContext::index_pos
unsigned int index_pos[2]
indexes in the sample tables
Definition: rl2.c:49
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1370
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: avcodec.h:3926
AVCodecParameters::channels
int channels
Audio only.
Definition: avcodec.h:3990
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:647
AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1020
avio_feof
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:358
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3888
AVPacket::stream_index
int stream_index
Definition: avcodec.h:1432
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:902
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1407
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1423
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