FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
cdxl.c
Go to the documentation of this file.
1 /*
2  * CDXL demuxer
3  * Copyright (c) 2011-2012 Paul B Mahol
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 
23 #include "libavutil/intreadwrite.h"
24 #include "libavutil/parseutils.h"
25 #include "libavutil/opt.h"
26 #include "avformat.h"
27 #include "internal.h"
28 
29 #define CDXL_HEADER_SIZE 32
30 
31 typedef struct CDXLDemuxContext {
32  AVClass *class;
34  char *framerate;
40  int64_t filesize;
42 
44 {
45  int score = AVPROBE_SCORE_EXTENSION + 10;
46 
47  if (p->buf_size < CDXL_HEADER_SIZE)
48  return 0;
49 
50  /* reserved bytes should always be set to 0 */
51  if (AV_RN64(&p->buf[24]) || AV_RN16(&p->buf[10]))
52  return 0;
53 
54  /* check type */
55  if (p->buf[0] != 1)
56  return 0;
57 
58  /* check palette size */
59  if (AV_RB16(&p->buf[20]) > 512)
60  return 0;
61 
62  /* check number of planes */
63  if (p->buf[18] || !p->buf[19])
64  return 0;
65 
66  /* check widh and height */
67  if (!AV_RN16(&p->buf[14]) || !AV_RN16(&p->buf[16]))
68  return 0;
69 
70  /* chunk size */
71  if (AV_RB32(&p->buf[2]) < AV_RB16(&p->buf[22]) + AV_RB16(&p->buf[20]) + CDXL_HEADER_SIZE)
72  return 0;
73 
74  /* previous chunk size */
75  if (AV_RN32(&p->buf[6]))
76  score /= 2;
77 
78  /* current frame number, usually starts from 1 */
79  if (AV_RB16(&p->buf[12]) != 1)
80  score /= 2;
81 
82  return score;
83 }
84 
86 {
87  CDXLDemuxContext *cdxl = s->priv_data;
88  int ret;
89 
90  if (cdxl->framerate && (ret = av_parse_video_rate(&cdxl->fps, cdxl->framerate)) < 0) {
92  "Could not parse framerate: %s.\n", cdxl->framerate);
93  return ret;
94  }
95 
96  cdxl->read_chunk = 0;
97  cdxl->video_stream_index = -1;
98  cdxl->audio_stream_index = -1;
99 
100  cdxl->filesize = avio_size(s->pb);
101 
103 
104  return 0;
105 }
106 
108 {
109  CDXLDemuxContext *cdxl = s->priv_data;
110  AVIOContext *pb = s->pb;
111  uint32_t current_size, video_size, image_size;
112  uint16_t audio_size, palette_size, width, height;
113  int64_t pos;
114  int frames, ret;
115 
116  if (avio_feof(pb))
117  return AVERROR_EOF;
118 
119  pos = avio_tell(pb);
120  if (!cdxl->read_chunk &&
122  return AVERROR_EOF;
123  if (cdxl->header[0] != 1) {
124  av_log(s, AV_LOG_ERROR, "non-standard cdxl file\n");
125  return AVERROR_INVALIDDATA;
126  }
127 
128  current_size = AV_RB32(&cdxl->header[2]);
129  width = AV_RB16(&cdxl->header[14]);
130  height = AV_RB16(&cdxl->header[16]);
131  palette_size = AV_RB16(&cdxl->header[20]);
132  audio_size = AV_RB16(&cdxl->header[22]);
133  if (FFALIGN(width, 16) * (uint64_t)height * cdxl->header[19] > INT_MAX)
134  return AVERROR_INVALIDDATA;
135  image_size = FFALIGN(width, 16) * height * cdxl->header[19] / 8;
136  video_size = palette_size + image_size;
137 
138  if (palette_size > 512)
139  return AVERROR_INVALIDDATA;
140  if (current_size < (uint64_t)audio_size + video_size + CDXL_HEADER_SIZE)
141  return AVERROR_INVALIDDATA;
142 
143  if (cdxl->read_chunk && audio_size) {
144  if (cdxl->audio_stream_index == -1) {
145  AVStream *st = avformat_new_stream(s, NULL);
146  if (!st)
147  return AVERROR(ENOMEM);
148 
150  st->codec->codec_tag = 0;
152  if (cdxl->header[1] & 0x10) {
153  st->codec->channels = 2;
155  } else {
156  st->codec->channels = 1;
158  }
159  st->codec->sample_rate = cdxl->sample_rate;
160  st->start_time = 0;
161  cdxl->audio_stream_index = st->index;
162  avpriv_set_pts_info(st, 64, 1, cdxl->sample_rate);
163  }
164 
165  ret = av_get_packet(pb, pkt, audio_size);
166  if (ret < 0)
167  return ret;
168  pkt->stream_index = cdxl->audio_stream_index;
169  pkt->pos = pos;
170  pkt->duration = audio_size;
171  cdxl->read_chunk = 0;
172  } else {
173  if (cdxl->video_stream_index == -1) {
174  AVStream *st = avformat_new_stream(s, NULL);
175  if (!st)
176  return AVERROR(ENOMEM);
177 
179  st->codec->codec_tag = 0;
181  st->codec->width = width;
182  st->codec->height = height;
183 
184  if (audio_size + video_size && cdxl->filesize > 0) {
185  frames = cdxl->filesize / (audio_size + video_size);
186 
187  if(cdxl->framerate)
188  st->duration = frames;
189  else
190  st->duration = frames * (int64_t)audio_size;
191  }
192  st->start_time = 0;
193  cdxl->video_stream_index = st->index;
194  if (cdxl->framerate)
195  avpriv_set_pts_info(st, 64, cdxl->fps.den, cdxl->fps.num);
196  else
197  avpriv_set_pts_info(st, 64, 1, cdxl->sample_rate);
198  }
199 
200  if (av_new_packet(pkt, video_size + CDXL_HEADER_SIZE) < 0)
201  return AVERROR(ENOMEM);
202  memcpy(pkt->data, cdxl->header, CDXL_HEADER_SIZE);
203  ret = avio_read(pb, pkt->data + CDXL_HEADER_SIZE, video_size);
204  if (ret < 0) {
205  av_free_packet(pkt);
206  return ret;
207  }
209  pkt->stream_index = cdxl->video_stream_index;
210  pkt->flags |= AV_PKT_FLAG_KEY;
211  pkt->pos = pos;
212  pkt->duration = cdxl->framerate ? 1 : audio_size ? audio_size : 220;
213  cdxl->read_chunk = audio_size;
214  }
215 
216  if (!cdxl->read_chunk)
217  avio_skip(pb, current_size - audio_size - video_size - CDXL_HEADER_SIZE);
218  return ret;
219 }
220 
221 #define OFFSET(x) offsetof(CDXLDemuxContext, x)
222 static const AVOption cdxl_options[] = {
223  { "sample_rate", "", OFFSET(sample_rate), AV_OPT_TYPE_INT, { .i64 = 11025 }, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM },
224  { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, AV_OPT_FLAG_DECODING_PARAM },
225  { NULL },
226 };
227 
228 static const AVClass cdxl_demuxer_class = {
229  .class_name = "CDXL demuxer",
230  .item_name = av_default_item_name,
231  .option = cdxl_options,
232  .version = LIBAVUTIL_VERSION_INT,
233 };
234 
236  .name = "cdxl",
237  .long_name = NULL_IF_CONFIG_SMALL("Commodore CDXL video"),
238  .priv_data_size = sizeof(CDXLDemuxContext),
242  .extensions = "cdxl,xl",
244  .priv_class = &cdxl_demuxer_class,
245 };