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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  return AVPROBE_SCORE_MAX;
65 }
66 
68 {
69  BVID_DemuxContext *vid = s->priv_data;
70  AVIOContext *pb = s->pb;
71 
72  /* load main header. Contents:
73  * bytes: 'V' 'I' 'D'
74  * int16s: always_512, nframes, width, height, delay, always_14
75  */
76  avio_skip(pb, 5);
77  vid->nframes = avio_rl16(pb);
78  vid->width = avio_rl16(pb);
79  vid->height = avio_rl16(pb);
81  avio_rl16(pb);
82 
83  // wait until the first packet to create each stream
84  vid->video_index = -1;
85  vid->audio_index = -1;
88 
89  return 0;
90 }
91 
92 #define BUFFER_PADDING_SIZE 1000
94  uint8_t block_type, AVFormatContext *s)
95 {
96  uint8_t * vidbuf_start = NULL;
97  int vidbuf_nbytes = 0;
98  int code;
99  int bytes_copied = 0;
100  int position, duration, npixels;
101  unsigned int vidbuf_capacity;
102  int ret = 0;
103  AVStream *st;
104 
105  if (vid->video_index < 0) {
106  st = avformat_new_stream(s, NULL);
107  if (!st)
108  return AVERROR(ENOMEM);
109  vid->video_index = st->index;
110  if (vid->audio_index < 0) {
111  av_log_ask_for_sample(s, "No audio packet before first video "
112  "packet. Using default video time base.\n");
113  }
114  avpriv_set_pts_info(st, 64, 185, vid->sample_rate);
117  st->codec->width = vid->width;
118  st->codec->height = vid->height;
119  }
120  st = s->streams[vid->video_index];
121  npixels = st->codec->width * st->codec->height;
122 
123  vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
124  if(!vidbuf_start)
125  return AVERROR(ENOMEM);
126 
127  // save the file position for the packet, include block type
128  position = avio_tell(pb) - 1;
129 
130  vidbuf_start[vidbuf_nbytes++] = block_type;
131 
132  // get the current packet duration
133  duration = vid->bethsoft_global_delay + avio_rl16(pb);
134 
135  // set the y offset if it exists (decoder header data should be in data section)
136  if(block_type == VIDEO_YOFF_P_FRAME){
137  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) {
138  ret = AVERROR(EIO);
139  goto fail;
140  }
141  vidbuf_nbytes += 2;
142  }
143 
144  do{
145  vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
146  if(!vidbuf_start)
147  return AVERROR(ENOMEM);
148 
149  code = avio_r8(pb);
150  vidbuf_start[vidbuf_nbytes++] = code;
151 
152  if(code >= 0x80){ // rle sequence
153  if(block_type == VIDEO_I_FRAME)
154  vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);
155  } else if(code){ // plain sequence
156  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code) {
157  ret = AVERROR(EIO);
158  goto fail;
159  }
160  vidbuf_nbytes += code;
161  }
162  bytes_copied += code & 0x7F;
163  if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
164  // may contain a 0 byte even if read all pixels
165  if(avio_r8(pb))
166  avio_seek(pb, -1, SEEK_CUR);
167  break;
168  }
169  if (bytes_copied > npixels) {
170  ret = AVERROR_INVALIDDATA;
171  goto fail;
172  }
173  } while(code);
174 
175  // copy data into packet
176  if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0)
177  goto fail;
178  memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
179  av_free(vidbuf_start);
180 
181  pkt->pos = position;
182  pkt->stream_index = vid->video_index;
183  pkt->duration = duration;
184  if (block_type == VIDEO_I_FRAME)
185  pkt->flags |= AV_PKT_FLAG_KEY;
186 
187  /* if there is a new palette available, add it to packet side data */
188  if (vid->palette) {
191  if (pdata)
192  memcpy(pdata, vid->palette, BVID_PALETTE_SIZE);
193  av_freep(&vid->palette);
194  }
195 
196  vid->nframes--; // used to check if all the frames were read
197  return 0;
198 fail:
199  av_free(vidbuf_start);
200  return ret;
201 }
202 
204  AVPacket *pkt)
205 {
206  BVID_DemuxContext *vid = s->priv_data;
207  AVIOContext *pb = s->pb;
208  unsigned char block_type;
209  int audio_length;
210  int ret_value;
211 
212  if(vid->is_finished || url_feof(pb))
213  return AVERROR_EOF;
214 
215  block_type = avio_r8(pb);
216  switch(block_type){
217  case PALETTE_BLOCK:
218  if (vid->palette) {
219  av_log(s, AV_LOG_WARNING, "discarding unused palette\n");
220  av_freep(&vid->palette);
221  }
223  if (!vid->palette)
224  return AVERROR(ENOMEM);
226  av_freep(&vid->palette);
227  return AVERROR(EIO);
228  }
229  return vid_read_packet(s, pkt);
230 
231  case FIRST_AUDIO_BLOCK:
232  avio_rl16(pb);
233  // soundblaster DAC used for sample rate, as on specification page (link above)
234  vid->sample_rate = 1000000 / (256 - avio_r8(pb));
235  case AUDIO_BLOCK:
236  if (vid->audio_index < 0) {
238  if (!st)
239  return AVERROR(ENOMEM);
240  vid->audio_index = st->index;
243  st->codec->channels = 1;
245  st->codec->bits_per_coded_sample = 8;
246  st->codec->sample_rate = vid->sample_rate;
247  st->codec->bit_rate = 8 * st->codec->sample_rate;
248  st->start_time = 0;
249  avpriv_set_pts_info(st, 64, 1, vid->sample_rate);
250  }
251  audio_length = avio_rl16(pb);
252  if ((ret_value = av_get_packet(pb, pkt, audio_length)) != audio_length) {
253  if (ret_value < 0)
254  return ret_value;
255  av_log(s, AV_LOG_ERROR, "incomplete audio block\n");
256  return AVERROR(EIO);
257  }
258  pkt->stream_index = vid->audio_index;
259  pkt->duration = audio_length;
260  pkt->flags |= AV_PKT_FLAG_KEY;
261  return 0;
262 
263  case VIDEO_P_FRAME:
264  case VIDEO_YOFF_P_FRAME:
265  case VIDEO_I_FRAME:
266  return read_frame(vid, pb, pkt, block_type, s);
267 
268  case EOF_BLOCK:
269  if(vid->nframes != 0)
270  av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
271  vid->is_finished = 1;
272  return AVERROR(EIO);
273  default:
274  av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
275  block_type, block_type, block_type);
276  return AVERROR_INVALIDDATA;
277  }
278 }
279 
281 {
282  BVID_DemuxContext *vid = s->priv_data;
283  av_freep(&vid->palette);
284  return 0;
285 }
286 
288  .name = "bethsoftvid",
289  .long_name = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),
290  .priv_data_size = sizeof(BVID_DemuxContext),
295 };