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 "libavutil/mem.h"
40 #include "avformat.h"
41 #include "demux.h"
42 #include "internal.h"
43 
44 #define EXTRADATA1_SIZE (6 + 256 * 3) ///< video base, clr, palette
45 
46 #define FORM_TAG MKBETAG('F', 'O', 'R', 'M')
47 #define RLV2_TAG MKBETAG('R', 'L', 'V', '2')
48 #define RLV3_TAG MKBETAG('R', 'L', 'V', '3')
49 
50 typedef struct Rl2DemuxContext {
51  unsigned int index_pos[2]; ///< indexes in the sample tables
53 
54 
55 /**
56  * check if the file is in rl2 format
57  * @param p probe buffer
58  * @return 0 when the probe buffer does not contain rl2 data, > 0 otherwise
59  */
60 static int rl2_probe(const AVProbeData *p)
61 {
62 
63  if(AV_RB32(&p->buf[0]) != FORM_TAG)
64  return 0;
65 
66  if(AV_RB32(&p->buf[8]) != RLV2_TAG &&
67  AV_RB32(&p->buf[8]) != RLV3_TAG)
68  return 0;
69 
70  return AVPROBE_SCORE_MAX;
71 }
72 
73 /**
74  * read rl2 header data and setup the avstreams
75  * @param s demuxer context
76  * @return 0 on success, AVERROR otherwise
77  */
79 {
80  AVIOContext *pb = s->pb;
81  AVStream *st;
82  unsigned int frame_count;
83  unsigned int audio_frame_counter = 0;
84  unsigned int video_frame_counter = 0;
85  unsigned int back_size;
86  unsigned short sound_rate;
87  unsigned short rate;
88  unsigned short channels;
89  unsigned short def_sound_size;
90  unsigned int signature;
91  unsigned int pts_den = 11025; /* video only case */
92  unsigned int pts_num = 1103;
93  unsigned int* chunk_offset = NULL;
94  int* chunk_size = NULL;
95  int* audio_size = NULL;
96  int i;
97  int ret = 0;
98 
99  avio_skip(pb,4); /* skip FORM tag */
100  back_size = avio_rl32(pb); /**< get size of the background frame */
101  signature = avio_rb32(pb);
102  avio_skip(pb, 4); /* data size */
103  frame_count = avio_rl32(pb);
104 
105  /* disallow back_sizes and frame_counts that may lead to overflows later */
106  if(back_size > INT_MAX/2 || frame_count > INT_MAX / sizeof(uint32_t))
107  return AVERROR_INVALIDDATA;
108 
109  avio_skip(pb, 2); /* encoding method */
110  sound_rate = avio_rl16(pb);
111  rate = avio_rl16(pb);
112  channels = avio_rl16(pb);
113  def_sound_size = avio_rl16(pb);
114 
115  /** setup video stream */
116  st = avformat_new_stream(s, NULL);
117  if(!st)
118  return AVERROR(ENOMEM);
119 
122  st->codecpar->codec_tag = 0; /* no fourcc */
123  st->codecpar->width = 320;
124  st->codecpar->height = 200;
125 
126  /** allocate and fill extradata */
128 
129  if(signature == RLV3_TAG && back_size > 0)
130  st->codecpar->extradata_size += back_size;
131 
133  if (ret < 0)
134  return ret;
135 
136  /** setup audio stream if present */
137  if(sound_rate){
138  if (!channels || channels > 42) {
139  av_log(s, AV_LOG_ERROR, "Invalid number of channels: %d\n", channels);
140  return AVERROR_INVALIDDATA;
141  }
142 
143  pts_num = def_sound_size;
144  pts_den = rate;
145 
146  st = avformat_new_stream(s, NULL);
147  if (!st)
148  return AVERROR(ENOMEM);
151  st->codecpar->codec_tag = 1;
154  st->codecpar->sample_rate = rate;
157  st->codecpar->block_align = channels *
159  avpriv_set_pts_info(st,32,1,rate);
160  }
161 
162  avpriv_set_pts_info(s->streams[0], 32, pts_num, pts_den);
163 
164  chunk_size = av_malloc(frame_count * sizeof(uint32_t));
165  audio_size = av_malloc(frame_count * sizeof(uint32_t));
166  chunk_offset = av_malloc(frame_count * sizeof(uint32_t));
167 
168  if(!chunk_size || !audio_size || !chunk_offset){
169  av_free(chunk_size);
170  av_free(audio_size);
171  av_free(chunk_offset);
172  return AVERROR(ENOMEM);
173  }
174 
175  /** read offset and size tables */
176  for(i=0; i < frame_count;i++) {
177  if (avio_feof(pb)) {
179  goto end;
180  }
181  chunk_size[i] = avio_rl32(pb);
182  }
183  for(i=0; i < frame_count;i++) {
184  if (avio_feof(pb)) {
186  goto end;
187  }
188  chunk_offset[i] = avio_rl32(pb);
189  }
190  for(i=0; i < frame_count;i++) {
191  if (avio_feof(pb)) {
193  goto end;
194  }
195  audio_size[i] = avio_rl32(pb) & 0xFFFF;
196  }
197 
198  /** build the sample index */
199  for(i=0;i<frame_count;i++){
200  if(chunk_size[i] < 0 || audio_size[i] > chunk_size[i]){
202  break;
203  }
204 
205  if(sound_rate && audio_size[i]){
206  av_add_index_entry(s->streams[1], chunk_offset[i],
207  audio_frame_counter,audio_size[i], 0, AVINDEX_KEYFRAME);
208  audio_frame_counter += audio_size[i] / channels;
209  }
210  av_add_index_entry(s->streams[0], chunk_offset[i] + audio_size[i],
211  video_frame_counter,chunk_size[i]-audio_size[i],0,AVINDEX_KEYFRAME);
212  ++video_frame_counter;
213  }
214 
215 end:
216  av_free(chunk_size);
217  av_free(audio_size);
218  av_free(chunk_offset);
219 
220  return ret;
221 }
222 
223 /**
224  * read a single audio or video packet
225  * @param s demuxer context
226  * @param pkt the packet to be filled
227  * @return 0 on success, AVERROR otherwise
228  */
230  AVPacket *pkt)
231 {
232  Rl2DemuxContext *rl2 = s->priv_data;
233  AVIOContext *pb = s->pb;
235  int i;
236  int ret = 0;
237  int stream_id = -1;
238  int64_t pos = INT64_MAX;
239 
240  /** check if there is a valid video or audio entry that can be used */
241  for(i=0; i<s->nb_streams; i++){
242  const FFStream *const sti = ffstream(s->streams[i]);
243  if (rl2->index_pos[i] < sti->nb_index_entries
244  && sti->index_entries[ rl2->index_pos[i] ].pos < pos) {
245  sample = &sti->index_entries[ rl2->index_pos[i] ];
246  pos= sample->pos;
247  stream_id= i;
248  }
249  }
250 
251  if(stream_id == -1)
252  return AVERROR_EOF;
253 
254  ++rl2->index_pos[stream_id];
255 
256  /** position the stream (will probably be there anyway) */
257  avio_seek(pb, sample->pos, SEEK_SET);
258 
259  /** fill the packet */
260  ret = av_get_packet(pb, pkt, sample->size);
261  if(ret != sample->size){
262  return AVERROR(EIO);
263  }
264 
265  pkt->stream_index = stream_id;
266  pkt->pts = sample->timestamp;
267 
268  return ret;
269 }
270 
271 /**
272  * seek to a new timestamp
273  * @param s demuxer context
274  * @param stream_index index of the stream that should be seeked
275  * @param timestamp wanted timestamp
276  * @param flags direction and seeking mode
277  * @return 0 on success, -1 otherwise
278  */
279 static int rl2_read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
280 {
281  AVStream *st = s->streams[stream_index];
282  Rl2DemuxContext *rl2 = s->priv_data;
283  int i;
284  int index = av_index_search_timestamp(st, timestamp, flags);
285  if(index < 0)
286  return -1;
287 
288  rl2->index_pos[stream_index] = index;
289  timestamp = ffstream(st)->index_entries[index].timestamp;
290 
291  for(i=0; i < s->nb_streams; i++){
292  AVStream *st2 = s->streams[i];
294  av_rescale_q(timestamp, st->time_base, st2->time_base),
296 
297  if(index < 0)
298  index = 0;
299 
300  rl2->index_pos[i] = index;
301  }
302 
303  return 0;
304 }
305 
307  .p.name = "rl2",
308  .p.long_name = NULL_IF_CONFIG_SMALL("RL2"),
309  .priv_data_size = sizeof(Rl2DemuxContext),
314 };
AVERROR
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
FORM_TAG
#define FORM_TAG
Definition: rl2.c:46
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
rl2_read_header
static av_cold int rl2_read_header(AVFormatContext *s)
read rl2 header data and setup the avstreams
Definition: rl2.c:78
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:279
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:59
mathematics.h
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:313
AVIndexEntry
Definition: avformat.h:602
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
AVINDEX_KEYFRAME
#define AVINDEX_KEYFRAME
Definition: avformat.h:610
ff_get_extradata
int ff_get_extradata(void *logctx, 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: demux_utils.c:335
AVPROBE_SCORE_MAX
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:463
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:853
ffstream
static av_always_inline FFStream * ffstream(AVStream *st)
Definition: internal.h:417
read_seek
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
Definition: libcdio.c:151
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: seek.c:121
rl2_probe
static int rl2_probe(const AVProbeData *p)
check if the file is in rl2 format
Definition: rl2.c:60
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:714
signature
static const char signature[]
Definition: ipmovie.c:591
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:761
pkt
AVPacket * pkt
Definition: movenc.c:60
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:42
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AV_CODEC_ID_RL2
@ AV_CODEC_ID_RL2
Definition: codec_id.h:166
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
AVIndexEntry::timestamp
int64_t timestamp
Timestamp in AVStream.time_base units, preferably the time from which on correctly decoded frames are...
Definition: avformat.h:604
channels
channels
Definition: aptx.h:31
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
EXTRADATA1_SIZE
#define EXTRADATA1_SIZE
video base, clr, palette
Definition: rl2.c:44
AVFormatContext
Format I/O context.
Definition: avformat.h:1255
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:766
AVSEEK_FLAG_BACKWARD
#define AVSEEK_FLAG_BACKWARD
Definition: avformat.h:2445
read_header
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:550
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:782
NULL
#define NULL
Definition: coverity.c:32
FFStream::nb_index_entries
int nb_index_entries
Definition: internal.h:251
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:180
index
int index
Definition: gxfenc.c:90
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
AVCodecParameters::extradata_size
int extradata_size
Size of the extradata content in bytes.
Definition: codec_par.h:73
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:730
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
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:94
FFStream
Definition: internal.h:193
Rl2DemuxContext
Definition: rl2.c:50
Rl2DemuxContext::index_pos
unsigned int index_pos[2]
indexes in the sample tables
Definition: rl2.c:51
sample
#define sample
Definition: flacdsp_template.c:44
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:96
ff_rl2_demuxer
const FFInputFormat ff_rl2_demuxer
Definition: rl2.c:306
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:517
AVCodecParameters::height
int height
Definition: codec_par.h:135
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:191
demux.h
RLV3_TAG
#define RLV3_TAG
Definition: rl2.c:48
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:91
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:743
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:231
pos
unsigned int pos
Definition: spdifenc.c:414
avformat.h
AVIndexEntry::pos
int64_t pos
Definition: avformat.h:603
AVPacket::stream_index
int stream_index
Definition: packet.h:526
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
FFStream::index_entries
AVIndexEntry * index_entries
Only used if the format does not support seeking natively.
Definition: internal.h:249
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:30
AVCodecParameters::bits_per_coded_sample
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:110
mem.h
AV_CODEC_ID_PCM_U8
@ AV_CODEC_ID_PCM_U8
Definition: codec_id.h:333
RLV2_TAG
#define RLV2_TAG
Definition: rl2.c:47
av_free
#define av_free(p)
Definition: tableprint_vlc.h:33
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:501
FFInputFormat
Definition: demux.h:37
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
AVCodecParameters::bit_rate
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:97
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
rl2_read_packet
static int rl2_read_packet(AVFormatContext *s, AVPacket *pkt)
read a single audio or video packet
Definition: rl2.c:229
av_index_search_timestamp
int av_index_search_timestamp(AVStream *st, int64_t timestamp, int flags)
Get the index for a specific timestamp.
Definition: seek.c:244
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:346