FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
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 "internal.h"
27 #include "riff.h"
28 
29 #define DXA_EXTRA_SIZE 9
30 
31 typedef struct{
32  int frames;
33  int has_sound;
34  int bpc;
35  uint32_t bytes_left;
36  int64_t wavpos, vidpos;
37  int readvid;
38 }DXAContext;
39 
40 static int dxa_probe(AVProbeData *p)
41 {
42  int w, h;
43  if (p->buf_size < 15)
44  return 0;
45  w = AV_RB16(p->buf + 11);
46  h = AV_RB16(p->buf + 13);
47  /* check file header */
48  if (p->buf[0] == 'D' && p->buf[1] == 'E' &&
49  p->buf[2] == 'X' && p->buf[3] == 'A' &&
50  w && w <= 2048 && h && h <= 2048)
51  return AVPROBE_SCORE_MAX;
52  else
53  return 0;
54 }
55 
57 {
58  AVIOContext *pb = s->pb;
59  DXAContext *c = s->priv_data;
60  AVStream *st, *ast;
61  uint32_t tag;
62  int32_t fps;
63  int w, h;
64  int num, den;
65  int flags;
66  int ret;
67 
68  tag = avio_rl32(pb);
69  if (tag != MKTAG('D', 'E', 'X', 'A'))
70  return AVERROR_INVALIDDATA;
71  flags = avio_r8(pb);
72  c->frames = avio_rb16(pb);
73  if(!c->frames){
74  av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");
75  return AVERROR_INVALIDDATA;
76  }
77 
78  fps = avio_rb32(pb);
79  if(fps > 0){
80  den = 1000;
81  num = fps;
82  }else if (fps < 0){
83  den = 100000;
84  num = -fps;
85  }else{
86  den = 10;
87  num = 1;
88  }
89  w = avio_rb16(pb);
90  h = avio_rb16(pb);
91  c->has_sound = 0;
92 
93  st = avformat_new_stream(s, NULL);
94  if (!st)
95  return AVERROR(ENOMEM);
96 
97  // Parse WAV data header
98  if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){
99  uint32_t size, fsize;
100  c->has_sound = 1;
101  size = avio_rb32(pb);
102  c->vidpos = avio_tell(pb) + size;
103  avio_skip(pb, 16);
104  fsize = avio_rl32(pb);
105 
106  ast = avformat_new_stream(s, NULL);
107  if (!ast)
108  return AVERROR(ENOMEM);
109  ret = ff_get_wav_header(pb, ast->codec, fsize, 0);
110  if (ret < 0)
111  return ret;
112  if (ast->codec->sample_rate > 0)
113  avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);
114  // find 'data' chunk
115  while(avio_tell(pb) < c->vidpos && !avio_feof(pb)){
116  tag = avio_rl32(pb);
117  fsize = avio_rl32(pb);
118  if(tag == MKTAG('d', 'a', 't', 'a')) break;
119  avio_skip(pb, fsize);
120  }
121  c->bpc = (fsize + c->frames - 1) / c->frames;
122  if(ast->codec->block_align)
123  c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;
124  c->bytes_left = fsize;
125  c->wavpos = avio_tell(pb);
126  avio_seek(pb, c->vidpos, SEEK_SET);
127  }
128 
129  /* now we are ready: build format streams */
132  st->codec->width = w;
133  st->codec->height = h;
134  av_reduce(&den, &num, den, num, (1UL<<31)-1);
135  avpriv_set_pts_info(st, 33, num, den);
136  /* flags & 0x80 means that image is interlaced,
137  * flags & 0x40 means that image has double height
138  * either way set true height
139  */
140  if(flags & 0xC0){
141  st->codec->height >>= 1;
142  }
143  c->readvid = !c->has_sound;
144  c->vidpos = avio_tell(pb);
145  s->start_time = 0;
146  s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;
147  av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);
148 
149  return 0;
150 }
151 
153 {
154  DXAContext *c = s->priv_data;
155  int ret;
156  uint32_t size;
157  uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];
158  int pal_size = 0;
159 
160  if(!c->readvid && c->has_sound && c->bytes_left){
161  c->readvid = 1;
162  avio_seek(s->pb, c->wavpos, SEEK_SET);
163  size = FFMIN(c->bytes_left, c->bpc);
164  ret = av_get_packet(s->pb, pkt, size);
165  pkt->stream_index = 1;
166  if(ret != size)
167  return AVERROR(EIO);
168  c->bytes_left -= size;
169  c->wavpos = avio_tell(s->pb);
170  return 0;
171  }
172  avio_seek(s->pb, c->vidpos, SEEK_SET);
173  while(!avio_feof(s->pb) && c->frames){
174  if ((ret = avio_read(s->pb, buf, 4)) != 4) {
175  av_log(s, AV_LOG_ERROR, "failed reading chunk type\n");
176  return ret < 0 ? ret : AVERROR_INVALIDDATA;
177  }
178  switch(AV_RL32(buf)){
179  case MKTAG('N', 'U', 'L', 'L'):
180  if(av_new_packet(pkt, 4 + pal_size) < 0)
181  return AVERROR(ENOMEM);
182  pkt->stream_index = 0;
183  if(pal_size) memcpy(pkt->data, pal, pal_size);
184  memcpy(pkt->data + pal_size, buf, 4);
185  c->frames--;
186  c->vidpos = avio_tell(s->pb);
187  c->readvid = 0;
188  return 0;
189  case MKTAG('C', 'M', 'A', 'P'):
190  pal_size = 768+4;
191  memcpy(pal, buf, 4);
192  avio_read(s->pb, pal + 4, 768);
193  break;
194  case MKTAG('F', 'R', 'A', 'M'):
195  if ((ret = avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4)) != DXA_EXTRA_SIZE - 4) {
196  av_log(s, AV_LOG_ERROR, "failed reading dxa_extra\n");
197  return ret < 0 ? ret : AVERROR_INVALIDDATA;
198  }
199  size = AV_RB32(buf + 5);
200  if(size > 0xFFFFFF){
201  av_log(s, AV_LOG_ERROR, "Frame size is too big: %"PRIu32"\n",
202  size);
203  return AVERROR_INVALIDDATA;
204  }
205  if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)
206  return AVERROR(ENOMEM);
207  memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);
208  ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);
209  if(ret != size){
210  av_free_packet(pkt);
211  return AVERROR(EIO);
212  }
213  if(pal_size) memcpy(pkt->data, pal, pal_size);
214  pkt->stream_index = 0;
215  c->frames--;
216  c->vidpos = avio_tell(s->pb);
217  c->readvid = 0;
218  return 0;
219  default:
220  av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);
221  return AVERROR_INVALIDDATA;
222  }
223  }
224  return AVERROR_EOF;
225 }
226 
228  .name = "dxa",
229  .long_name = NULL_IF_CONFIG_SMALL("DXA"),
230  .priv_data_size = sizeof(DXAContext),
234 };