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bethsoftvid.c
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1 /*
2  * Bethsoft VID format Demuxer
3  * Copyright (c) 2007 Nicholas Tung
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  * @file
24  * @brief Bethesda Softworks VID (.vid) file demuxer
25  * @author Nicholas Tung [ntung (at. ntung com] (2007-03)
26  * @see http://wiki.multimedia.cx/index.php?title=Bethsoft_VID
27  * @see http://www.svatopluk.com/andux/docs/dfvid.html
28  */
29 
31 #include "libavutil/intreadwrite.h"
32 #include "avformat.h"
33 #include "internal.h"
35 
36 #define BVID_PALETTE_SIZE 3 * 256
37 
38 #define DEFAULT_SAMPLE_RATE 11111
39 
40 typedef struct BVID_DemuxContext
41 {
42  int nframes;
43  int sample_rate; /**< audio sample rate */
44  int width; /**< video width */
45  int height; /**< video height */
46  /** delay value between frames, added to individual frame delay.
47  * custom units, which will be added to other custom units (~=16ms according
48  * to free, unofficial documentation) */
50  int video_index; /**< video stream index */
51  int audio_index; /**< audio stream index */
53 
55 
57 
58 static int vid_probe(AVProbeData *p)
59 {
60  // little-endian VID tag, file starts with "VID\0"
61  if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))
62  return 0;
63 
64  if (p->buf[4] != 2)
65  return AVPROBE_SCORE_MAX / 4;
66 
67  return AVPROBE_SCORE_MAX;
68 }
69 
71 {
72  BVID_DemuxContext *vid = s->priv_data;
73  AVIOContext *pb = s->pb;
74 
75  /* load main header. Contents:
76  * bytes: 'V' 'I' 'D'
77  * int16s: always_512, nframes, width, height, delay, always_14
78  */
79  avio_skip(pb, 5);
80  vid->nframes = avio_rl16(pb);
81  vid->width = avio_rl16(pb);
82  vid->height = avio_rl16(pb);
84  avio_rl16(pb);
85 
86  // wait until the first packet to create each stream
87  vid->video_index = -1;
88  vid->audio_index = -1;
91 
92  return 0;
93 }
94 
95 #define BUFFER_PADDING_SIZE 1000
97  uint8_t block_type, AVFormatContext *s)
98 {
99  uint8_t * vidbuf_start = NULL;
100  int vidbuf_nbytes = 0;
101  int code;
102  int bytes_copied = 0;
103  int position, duration, npixels;
104  unsigned int vidbuf_capacity;
105  int ret = 0;
106  AVStream *st;
107 
108  if (vid->video_index < 0) {
109  st = avformat_new_stream(s, NULL);
110  if (!st)
111  return AVERROR(ENOMEM);
112  vid->video_index = st->index;
113  if (vid->audio_index < 0) {
114  avpriv_request_sample(s, "Using default video time base since "
115  "having no audio packet before the first "
116  "video packet");
117  }
118  avpriv_set_pts_info(st, 64, 185, vid->sample_rate);
121  st->codec->width = vid->width;
122  st->codec->height = vid->height;
123  }
124  st = s->streams[vid->video_index];
125  npixels = st->codec->width * st->codec->height;
126 
127  vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
128  if(!vidbuf_start)
129  return AVERROR(ENOMEM);
130 
131  // save the file position for the packet, include block type
132  position = avio_tell(pb) - 1;
133 
134  vidbuf_start[vidbuf_nbytes++] = block_type;
135 
136  // get the current packet duration
137  duration = vid->bethsoft_global_delay + avio_rl16(pb);
138 
139  // set the y offset if it exists (decoder header data should be in data section)
140  if(block_type == VIDEO_YOFF_P_FRAME){
141  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) {
142  ret = AVERROR(EIO);
143  goto fail;
144  }
145  vidbuf_nbytes += 2;
146  }
147 
148  do{
149  vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
150  if(!vidbuf_start)
151  return AVERROR(ENOMEM);
152 
153  code = avio_r8(pb);
154  vidbuf_start[vidbuf_nbytes++] = code;
155 
156  if(code >= 0x80){ // rle sequence
157  if(block_type == VIDEO_I_FRAME)
158  vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);
159  } else if(code){ // plain sequence
160  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code) {
161  ret = AVERROR(EIO);
162  goto fail;
163  }
164  vidbuf_nbytes += code;
165  }
166  bytes_copied += code & 0x7F;
167  if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
168  // may contain a 0 byte even if read all pixels
169  if(avio_r8(pb))
170  avio_seek(pb, -1, SEEK_CUR);
171  break;
172  }
173  if (bytes_copied > npixels) {
174  ret = AVERROR_INVALIDDATA;
175  goto fail;
176  }
177  } while(code);
178 
179  // copy data into packet
180  if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0)
181  goto fail;
182  memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
183 
184  pkt->pos = position;
185  pkt->stream_index = vid->video_index;
186  pkt->duration = duration;
187  if (block_type == VIDEO_I_FRAME)
188  pkt->flags |= AV_PKT_FLAG_KEY;
189 
190  /* if there is a new palette available, add it to packet side data */
191  if (vid->palette) {
194  if (!pdata) {
195  ret = AVERROR(ENOMEM);
196  av_log(s, AV_LOG_ERROR, "Failed to allocate palette side data\n");
197  goto fail;
198  }
199  memcpy(pdata, vid->palette, BVID_PALETTE_SIZE);
200 
201  av_freep(&vid->palette);
202  }
203 
204  vid->nframes--; // used to check if all the frames were read
205 fail:
206  av_free(vidbuf_start);
207  return ret;
208 }
209 
211  AVPacket *pkt)
212 {
213  BVID_DemuxContext *vid = s->priv_data;
214  AVIOContext *pb = s->pb;
215  unsigned char block_type;
216  int audio_length;
217  int ret_value;
218 
219  if(vid->is_finished || avio_feof(pb))
220  return AVERROR_EOF;
221 
222  block_type = avio_r8(pb);
223  switch(block_type){
224  case PALETTE_BLOCK:
225  if (vid->palette) {
226  av_log(s, AV_LOG_WARNING, "discarding unused palette\n");
227  av_freep(&vid->palette);
228  }
230  if (!vid->palette)
231  return AVERROR(ENOMEM);
233  av_freep(&vid->palette);
234  return AVERROR(EIO);
235  }
236  return vid_read_packet(s, pkt);
237 
238  case FIRST_AUDIO_BLOCK:
239  avio_rl16(pb);
240  // soundblaster DAC used for sample rate, as on specification page (link above)
241  vid->sample_rate = 1000000 / (256 - avio_r8(pb));
242  case AUDIO_BLOCK:
243  if (vid->audio_index < 0) {
245  if (!st)
246  return AVERROR(ENOMEM);
247  vid->audio_index = st->index;
250  st->codec->channels = 1;
252  st->codec->bits_per_coded_sample = 8;
253  st->codec->sample_rate = vid->sample_rate;
254  st->codec->bit_rate = 8 * st->codec->sample_rate;
255  st->start_time = 0;
256  avpriv_set_pts_info(st, 64, 1, vid->sample_rate);
257  }
258  audio_length = avio_rl16(pb);
259  if ((ret_value = av_get_packet(pb, pkt, audio_length)) != audio_length) {
260  if (ret_value < 0)
261  return ret_value;
262  av_log(s, AV_LOG_ERROR, "incomplete audio block\n");
263  return AVERROR(EIO);
264  }
265  pkt->stream_index = vid->audio_index;
266  pkt->duration = audio_length;
267  pkt->flags |= AV_PKT_FLAG_KEY;
268  return 0;
269 
270  case VIDEO_P_FRAME:
271  case VIDEO_YOFF_P_FRAME:
272  case VIDEO_I_FRAME:
273  return read_frame(vid, pb, pkt, block_type, s);
274 
275  case EOF_BLOCK:
276  if(vid->nframes != 0)
277  av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
278  vid->is_finished = 1;
279  return AVERROR(EIO);
280  default:
281  av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
282  block_type, block_type, block_type);
283  return AVERROR_INVALIDDATA;
284  }
285 }
286 
288 {
289  BVID_DemuxContext *vid = s->priv_data;
290  av_freep(&vid->palette);
291  return 0;
292 }
293 
295  .name = "bethsoftvid",
296  .long_name = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),
297  .priv_data_size = sizeof(BVID_DemuxContext),
302 };