FFmpeg
dxa.c
Go to the documentation of this file.
1 /*
2  * DXA demuxer
3  * Copyright (c) 2007 Konstantin Shishkov
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 #include <inttypes.h>
23 
24 #include "libavutil/intreadwrite.h"
25 #include "avformat.h"
26 #include "avio_internal.h"
27 #include "demux.h"
28 #include "internal.h"
29 #include "riff.h"
30 
31 #define DXA_EXTRA_SIZE 9
32 
33 typedef struct DXAContext {
34  int frames;
35  int has_sound;
36  int bpc;
37  uint32_t bytes_left;
38  int64_t wavpos, vidpos;
39  int readvid;
40 }DXAContext;
41 
42 static int dxa_probe(const AVProbeData *p)
43 {
44  int w, h;
45  if (p->buf_size < 15)
46  return 0;
47  w = AV_RB16(p->buf + 11);
48  h = AV_RB16(p->buf + 13);
49  /* check file header */
50  if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
51  p->buf[2] == 'X' && p->buf[3] == 'A' &&
52  w && w <= 2048 && h && h <= 2048)
53  return AVPROBE_SCORE_MAX;
54  else
55  return 0;
56 }
57 
58 static int dxa_read_header(AVFormatContext *s)
59 {
60  AVIOContext *pb = s->pb;
61  DXAContext *c = s->priv_data;
62  AVStream *st, *ast;
63  uint32_t tag;
64  int32_t fps;
65  int w, h;
66  int num, den;
67  int flags;
68  int ret;
69 
70  tag = avio_rl32(pb);
71  if (tag != MKTAG('D', 'E', 'X', 'A'))
72  return AVERROR_INVALIDDATA;
73  flags = avio_r8(pb);
74  c->frames = avio_rb16(pb);
75  if(!c->frames){
76  av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
77  return AVERROR_INVALIDDATA;
78  }
79 
80  fps = avio_rb32(pb);
81  if(fps > 0){
82  den = 1000;
83  num = fps;
84  }else if (fps < 0 && fps > INT_MIN){
85  den = 100000;
86  num = -fps;
87  }else{
88  den = 10;
89  num = 1;
90  }
91  w = avio_rb16(pb);
92  h = avio_rb16(pb);
93  c->has_sound = 0;
94 
95  st = avformat_new_stream(s, NULL);
96  if (!st)
97  return AVERROR(ENOMEM);
98 
99  // Parse WAV data header
100  if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
101  uint32_t size, fsize;
102  c->has_sound = 1;
103  size = avio_rb32(pb);
104  c->vidpos = avio_tell(pb) + size;
105  avio_skip(pb, 16);
106  fsize = avio_rl32(pb);
107 
108  ast = avformat_new_stream(s, NULL);
109  if (!ast)
110  return AVERROR(ENOMEM);
111  ret = ff_get_wav_header(s, pb, ast->codecpar, fsize, 0);
112  if (ret < 0)
113  return ret;
114  if (ast->codecpar->sample_rate > 0)
115  avpriv_set_pts_info(ast, 64, 1, ast->codecpar->sample_rate);
116  // find 'data' chunk
117  while(avio_tell(pb) < c->vidpos && !avio_feof(pb)){
118  tag = avio_rl32(pb);
119  fsize = avio_rl32(pb);
120  if(tag == MKTAG('d', 'a', 't', 'a')) break;
121  avio_skip(pb, fsize);
122  }
123  c->bpc = (fsize + (int64_t)c->frames - 1) / c->frames;
124  if (c->bpc < 0)
125  return AVERROR_INVALIDDATA;
126  if(ast->codecpar->block_align) {
127  if (c->bpc > INT_MAX - ast->codecpar->block_align + 1)
128  return AVERROR_INVALIDDATA;
129  c->bpc = ((c->bpc - 1 + ast->codecpar->block_align) / ast->codecpar->block_align) * ast->codecpar->block_align;
130  }
131  c->bytes_left = fsize;
132  c->wavpos = avio_tell(pb);
133  avio_seek(pb, c->vidpos, SEEK_SET);
134  }
135 
136  /* now we are ready: build format streams */
137  st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
138  st->codecpar->codec_id = AV_CODEC_ID_DXA;
139  st->codecpar->width = w;
140  st->codecpar->height = h;
141  av_reduce(&den, &num, den, num, (1UL<<31)-1);
142  avpriv_set_pts_info(st, 33, num, den);
143  /* flags & 0x80 means that image is interlaced,
144  * flags & 0x40 means that image has double height
145  * either way set true height
146  */
147  if(flags & 0xC0){
148  st->codecpar->height >>= 1;
149  }
150  c->readvid = !c->has_sound;
151  c->vidpos = avio_tell(pb);
152  s->start_time = 0;
153  s->duration = av_rescale(c->frames, AV_TIME_BASE * (int64_t)num, den);
154  av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
155 
156  return 0;
157 }
158 
159 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
160 {
161  DXAContext *c = s->priv_data;
162  int ret;
163  uint32_t size;
164  uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
165  int pal_size = 0;
166 
167  if(!c->readvid && c->has_sound && c->bytes_left){
168  c->readvid = 1;
169  avio_seek(s->pb, c->wavpos, SEEK_SET);
170  size = FFMIN(c->bytes_left, c->bpc);
171  ret = av_get_packet(s->pb, pkt, size);
172  pkt->stream_index = 1;
173  if(ret != size)
174  return AVERROR_INVALIDDATA;
175  c->bytes_left -= size;
176  c->wavpos = avio_tell(s->pb);
177  return 0;
178  }
179  avio_seek(s->pb, c->vidpos, SEEK_SET);
180  while(!avio_feof(s->pb) && c->frames){
181  uint32_t tag;
182  if ((ret = avio_read(s->pb, buf, 4)) != 4) {
183  av_log(s, AV_LOG_ERROR, "failed reading chunk type\n");
184  return ret < 0 ? ret : AVERROR_INVALIDDATA;
185  }
186  tag = AV_RL32(buf);
187  switch (tag) {
188  case MKTAG('N', 'U', 'L', 'L'):
189  if ((ret = av_new_packet(pkt, 4 + pal_size)) < 0)
190  return ret;
191  pkt->stream_index = 0;
192  if(pal_size) memcpy(pkt->data, pal, pal_size);
193  memcpy(pkt->data + pal_size, buf, 4);
194  c->frames--;
195  c->vidpos = avio_tell(s->pb);
196  c->readvid = 0;
197  return 0;
198  case MKTAG('C', 'M', 'A', 'P'):
199  pal_size = 768+4;
200  memcpy(pal, buf, 4);
201  avio_read(s->pb, pal + 4, 768);
202  break;
203  case MKTAG('F', 'R', 'A', 'M'):
204  if ((ret = avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4)) != DXA_EXTRA_SIZE - 4) {
205  av_log(s, AV_LOG_ERROR, "failed reading dxa_extra\n");
206  return ret < 0 ? ret : AVERROR_INVALIDDATA;
207  }
208  size = AV_RB32(buf + 5);
209  if(size > 0xFFFFFF){
210  av_log(s, AV_LOG_ERROR, "Frame size is too big: %"PRIu32"\n",
211  size);
212  return AVERROR_INVALIDDATA;
213  }
214  ret = av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size);
215  if (ret < 0)
216  return ret;
217  memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
218  ret = ffio_read_size(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
219  if (ret < 0)
220  return ret;
221  if(pal_size) memcpy(pkt->data, pal, pal_size);
222  pkt->stream_index = 0;
223  c->frames--;
224  c->vidpos = avio_tell(s->pb);
225  c->readvid = 0;
226  return 0;
227  default:
228  av_log(s, AV_LOG_ERROR, "Unknown tag %s\n", av_fourcc2str(tag));
229  return AVERROR_INVALIDDATA;
230  }
231  }
232  return AVERROR_EOF;
233 }
234 
235 const FFInputFormat ff_dxa_demuxer = {
236  .p.name = "dxa",
237  .p.long_name = NULL_IF_CONFIG_SMALL("DXA"),
238  .priv_data_size = sizeof(DXAContext),
239  .read_probe = dxa_probe,
240  .read_header = dxa_read_header,
241  .read_packet = dxa_read_packet,
242 };
flags
const SwsFlags flags[]
Definition: swscale.c:61
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
DXAContext::wavpos
int64_t wavpos
Definition: dxa.c:38
DXAContext::bytes_left
uint32_t bytes_left
Definition: dxa.c:37
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
int64_t
long long int64_t
Definition: coverity.c:34
w
uint8_t w
Definition: llviddspenc.c:38
DXAContext::frames
int frames
Definition: dxa.c:34
AVPacket::data
uint8_t * data
Definition: packet.h:588
DXAContext::vidpos
int64_t vidpos
Definition: dxa.c:38
ff_dxa_demuxer
const FFInputFormat ff_dxa_demuxer
Definition: dxa.c:235
dxa_probe
static int dxa_probe(const AVProbeData *p)
Definition: dxa.c:42
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:777
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:494
av_reduce
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
Definition: rational.c:35
DXAContext::has_sound
int has_sound
Definition: dxa.c:35
avio_rb32
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:764
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:210
read_packet
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_read_callback.c:42
DXAContext::bpc
int bpc
Definition: dxa.c:36
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: packet.c:98
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:549
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:231
fsize
static int64_t fsize(FILE *f)
Definition: audiomatch.c:29
AVFormatContext
Format I/O context.
Definition: avformat.h:1264
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:767
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
dxa_read_packet
static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: dxa.c:159
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:733
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
size
int size
Definition: twinvq_data.h:10344
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
DXA_EXTRA_SIZE
#define DXA_EXTRA_SIZE
Definition: dxa.c:31
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:51
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:606
read_header
static int read_header(FFV1Context *f, RangeCoder *c)
Definition: ffv1dec.c:498
AV_CODEC_ID_DXA
@ AV_CODEC_ID_DXA
Definition: codec_id.h:150
avio_internal.h
AVCodecParameters::height
int height
Definition: codec_par.h:135
AV_TIME_BASE
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:253
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:191
DXAContext
Definition: dxa.c:33
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
demux.h
ff_get_wav_header
int ff_get_wav_header(AVFormatContext *s, AVIOContext *pb, AVCodecParameters *par, int size, int big_endian)
Definition: riffdec.c:95
av_rescale
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
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:98
tag
uint32_t tag
Definition: movenc.c:2032
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:744
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:236
avio_rb16
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:749
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:615
Windows::Graphics::DirectX::Direct3D11::p
IDirect3DDxgiInterfaceAccess _COM_Outptr_ void ** p
Definition: vsrc_gfxcapture_winrt.hpp:53
AVPacket::stream_index
int stream_index
Definition: packet.h:590
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:321
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:200
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:30
dxa_read_header
static int dxa_read_header(AVFormatContext *s)
Definition: dxa.c:58
DXAContext::readvid
int readvid
Definition: dxa.c:39
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:565
riff.h
FFInputFormat
Definition: demux.h:47
int32_t
int32_t
Definition: audioconvert.c:56
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
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
ffio_read_size
int ffio_read_size(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:665
h
h
Definition: vp9dsp_template.c:2070
AV_RB16
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_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98
av_fourcc2str
#define av_fourcc2str(fourcc)
Definition: avutil.h:347
avio_feof
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:349
Generated on Sun Nov 30 2025 19:21:56 for FFmpeg by   doxygen 1.8.17