idroqdec.c
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1 /*
2  * id RoQ (.roq) File Demuxer
3  * Copyright (c) 2003 The ffmpeg Project
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
30 #include "libavutil/intreadwrite.h"
31 #include "avformat.h"
32 #include "internal.h"
33 
34 #define RoQ_MAGIC_NUMBER 0x1084
35 #define RoQ_CHUNK_PREAMBLE_SIZE 8
36 #define RoQ_AUDIO_SAMPLE_RATE 22050
37 #define RoQ_CHUNKS_TO_SCAN 30
38 
39 #define RoQ_INFO 0x1001
40 #define RoQ_QUAD_CODEBOOK 0x1002
41 #define RoQ_QUAD_VQ 0x1011
42 #define RoQ_SOUND_MONO 0x1020
43 #define RoQ_SOUND_STEREO 0x1021
44 
45 typedef struct RoqDemuxContext {
46 
48  int width;
49  int height;
51 
54 
55  int64_t video_pts;
56  unsigned int audio_frame_count;
57 
59 
60 static int roq_probe(AVProbeData *p)
61 {
62  if ((AV_RL16(&p->buf[0]) != RoQ_MAGIC_NUMBER) ||
63  (AV_RL32(&p->buf[2]) != 0xFFFFFFFF))
64  return 0;
65 
66  return AVPROBE_SCORE_MAX;
67 }
68 
71 {
72  RoqDemuxContext *roq = s->priv_data;
73  AVIOContext *pb = s->pb;
74  unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];
75 
76  /* get the main header */
77  if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
79  return AVERROR(EIO);
80  roq->frame_rate = AV_RL16(&preamble[6]);
81 
82  /* init private context parameters */
83  roq->width = roq->height = roq->audio_channels = roq->video_pts =
84  roq->audio_frame_count = 0;
85  roq->audio_stream_index = -1;
86  roq->video_stream_index = -1;
87 
89 
90  return 0;
91 }
92 
94  AVPacket *pkt)
95 {
96  RoqDemuxContext *roq = s->priv_data;
97  AVIOContext *pb = s->pb;
98  int ret = 0;
99  unsigned int chunk_size;
100  unsigned int chunk_type;
101  unsigned int codebook_size;
102  unsigned char preamble[RoQ_CHUNK_PREAMBLE_SIZE];
103  int packet_read = 0;
104  int64_t codebook_offset;
105 
106  while (!packet_read) {
107 
108  if (s->pb->eof_reached)
109  return AVERROR(EIO);
110 
111  /* get the next chunk preamble */
112  if ((ret = avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE)) !=
114  return AVERROR(EIO);
115 
116  chunk_type = AV_RL16(&preamble[0]);
117  chunk_size = AV_RL32(&preamble[2]);
118  if(chunk_size > INT_MAX)
119  return AVERROR_INVALIDDATA;
120 
121  switch (chunk_type) {
122 
123  case RoQ_INFO:
124  if (roq->video_stream_index == -1) {
126  if (!st)
127  return AVERROR(ENOMEM);
128  avpriv_set_pts_info(st, 63, 1, roq->frame_rate);
129  roq->video_stream_index = st->index;
131  st->codec->codec_id = CODEC_ID_ROQ;
132  st->codec->codec_tag = 0; /* no fourcc */
133 
135  return AVERROR(EIO);
136  st->codec->width = roq->width = AV_RL16(preamble);
137  st->codec->height = roq->height = AV_RL16(preamble + 2);
138  break;
139  }
140  /* don't care about this chunk anymore */
142  break;
143 
144  case RoQ_QUAD_CODEBOOK:
145  /* packet needs to contain both this codebook and next VQ chunk */
146  codebook_offset = avio_tell(pb) - RoQ_CHUNK_PREAMBLE_SIZE;
147  codebook_size = chunk_size;
148  avio_skip(pb, codebook_size);
149  if (avio_read(pb, preamble, RoQ_CHUNK_PREAMBLE_SIZE) !=
151  return AVERROR(EIO);
152  chunk_size = AV_RL32(&preamble[2]) + RoQ_CHUNK_PREAMBLE_SIZE * 2 +
153  codebook_size;
154 
155  /* rewind */
156  avio_seek(pb, codebook_offset, SEEK_SET);
157 
158  /* load up the packet */
159  ret= av_get_packet(pb, pkt, chunk_size);
160  if (ret != chunk_size)
161  return AVERROR(EIO);
162  pkt->stream_index = roq->video_stream_index;
163  pkt->pts = roq->video_pts++;
164 
165  packet_read = 1;
166  break;
167 
168  case RoQ_SOUND_MONO:
169  case RoQ_SOUND_STEREO:
170  if (roq->audio_stream_index == -1) {
172  if (!st)
173  return AVERROR(ENOMEM);
175  roq->audio_stream_index = st->index;
178  st->codec->codec_tag = 0; /* no tag */
179  st->codec->channels = roq->audio_channels = chunk_type == RoQ_SOUND_STEREO ? 2 : 1;
181  st->codec->bits_per_coded_sample = 16;
182  st->codec->bit_rate = st->codec->channels * st->codec->sample_rate *
185  }
186  case RoQ_QUAD_VQ:
187  /* load up the packet */
188  if (av_new_packet(pkt, chunk_size + RoQ_CHUNK_PREAMBLE_SIZE))
189  return AVERROR(EIO);
190  /* copy over preamble */
191  memcpy(pkt->data, preamble, RoQ_CHUNK_PREAMBLE_SIZE);
192 
193  if (chunk_type == RoQ_QUAD_VQ) {
194  pkt->stream_index = roq->video_stream_index;
195  pkt->pts = roq->video_pts++;
196  } else {
197  pkt->stream_index = roq->audio_stream_index;
198  pkt->pts = roq->audio_frame_count;
199  roq->audio_frame_count += (chunk_size / roq->audio_channels);
200  }
201 
202  pkt->pos= avio_tell(pb);
203  ret = avio_read(pb, pkt->data + RoQ_CHUNK_PREAMBLE_SIZE,
204  chunk_size);
205  if (ret != chunk_size)
206  ret = AVERROR(EIO);
207 
208  packet_read = 1;
209  break;
210 
211  default:
212  av_log(s, AV_LOG_ERROR, " unknown RoQ chunk (%04X)\n", chunk_type);
213  return AVERROR_INVALIDDATA;
214  }
215  }
216 
217  return ret;
218 }
219 
221  .name = "RoQ",
222  .long_name = NULL_IF_CONFIG_SMALL("id RoQ format"),
223  .priv_data_size = sizeof(RoqDemuxContext),
227 };