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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  avpriv_request_sample(s, "Using default video time base since "
112  "having no audio packet before the first "
113  "video packet");
114  }
115  avpriv_set_pts_info(st, 64, 185, vid->sample_rate);
118  st->codec->width = vid->width;
119  st->codec->height = vid->height;
120  }
121  st = s->streams[vid->video_index];
122  npixels = st->codec->width * st->codec->height;
123 
124  vidbuf_start = av_malloc(vidbuf_capacity = BUFFER_PADDING_SIZE);
125  if(!vidbuf_start)
126  return AVERROR(ENOMEM);
127 
128  // save the file position for the packet, include block type
129  position = avio_tell(pb) - 1;
130 
131  vidbuf_start[vidbuf_nbytes++] = block_type;
132 
133  // get the current packet duration
134  duration = vid->bethsoft_global_delay + avio_rl16(pb);
135 
136  // set the y offset if it exists (decoder header data should be in data section)
137  if(block_type == VIDEO_YOFF_P_FRAME){
138  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], 2) != 2) {
139  ret = AVERROR(EIO);
140  goto fail;
141  }
142  vidbuf_nbytes += 2;
143  }
144 
145  do{
146  vidbuf_start = av_fast_realloc(vidbuf_start, &vidbuf_capacity, vidbuf_nbytes + BUFFER_PADDING_SIZE);
147  if(!vidbuf_start)
148  return AVERROR(ENOMEM);
149 
150  code = avio_r8(pb);
151  vidbuf_start[vidbuf_nbytes++] = code;
152 
153  if(code >= 0x80){ // rle sequence
154  if(block_type == VIDEO_I_FRAME)
155  vidbuf_start[vidbuf_nbytes++] = avio_r8(pb);
156  } else if(code){ // plain sequence
157  if (avio_read(pb, &vidbuf_start[vidbuf_nbytes], code) != code) {
158  ret = AVERROR(EIO);
159  goto fail;
160  }
161  vidbuf_nbytes += code;
162  }
163  bytes_copied += code & 0x7F;
164  if(bytes_copied == npixels){ // sometimes no stop character is given, need to keep track of bytes copied
165  // may contain a 0 byte even if read all pixels
166  if(avio_r8(pb))
167  avio_seek(pb, -1, SEEK_CUR);
168  break;
169  }
170  if (bytes_copied > npixels) {
171  ret = AVERROR_INVALIDDATA;
172  goto fail;
173  }
174  } while(code);
175 
176  // copy data into packet
177  if ((ret = av_new_packet(pkt, vidbuf_nbytes)) < 0)
178  goto fail;
179  memcpy(pkt->data, vidbuf_start, vidbuf_nbytes);
180  av_free(vidbuf_start);
181 
182  pkt->pos = position;
183  pkt->stream_index = vid->video_index;
184  pkt->duration = duration;
185  if (block_type == VIDEO_I_FRAME)
186  pkt->flags |= AV_PKT_FLAG_KEY;
187 
188  /* if there is a new palette available, add it to packet side data */
189  if (vid->palette) {
192  if (pdata)
193  memcpy(pdata, vid->palette, BVID_PALETTE_SIZE);
194  av_freep(&vid->palette);
195  }
196 
197  vid->nframes--; // used to check if all the frames were read
198  return 0;
199 fail:
200  av_free(vidbuf_start);
201  return ret;
202 }
203 
205  AVPacket *pkt)
206 {
207  BVID_DemuxContext *vid = s->priv_data;
208  AVIOContext *pb = s->pb;
209  unsigned char block_type;
210  int audio_length;
211  int ret_value;
212 
213  if(vid->is_finished || url_feof(pb))
214  return AVERROR_EOF;
215 
216  block_type = avio_r8(pb);
217  switch(block_type){
218  case PALETTE_BLOCK:
219  if (vid->palette) {
220  av_log(s, AV_LOG_WARNING, "discarding unused palette\n");
221  av_freep(&vid->palette);
222  }
224  if (!vid->palette)
225  return AVERROR(ENOMEM);
227  av_freep(&vid->palette);
228  return AVERROR(EIO);
229  }
230  return vid_read_packet(s, pkt);
231 
232  case FIRST_AUDIO_BLOCK:
233  avio_rl16(pb);
234  // soundblaster DAC used for sample rate, as on specification page (link above)
235  vid->sample_rate = 1000000 / (256 - avio_r8(pb));
236  case AUDIO_BLOCK:
237  if (vid->audio_index < 0) {
238  AVStream *st = avformat_new_stream(s, NULL);
239  if (!st)
240  return AVERROR(ENOMEM);
241  vid->audio_index = st->index;
244  st->codec->channels = 1;
246  st->codec->bits_per_coded_sample = 8;
247  st->codec->sample_rate = vid->sample_rate;
248  st->codec->bit_rate = 8 * st->codec->sample_rate;
249  st->start_time = 0;
250  avpriv_set_pts_info(st, 64, 1, vid->sample_rate);
251  }
252  audio_length = avio_rl16(pb);
253  if ((ret_value = av_get_packet(pb, pkt, audio_length)) != audio_length) {
254  if (ret_value < 0)
255  return ret_value;
256  av_log(s, AV_LOG_ERROR, "incomplete audio block\n");
257  return AVERROR(EIO);
258  }
259  pkt->stream_index = vid->audio_index;
260  pkt->duration = audio_length;
261  pkt->flags |= AV_PKT_FLAG_KEY;
262  return 0;
263 
264  case VIDEO_P_FRAME:
265  case VIDEO_YOFF_P_FRAME:
266  case VIDEO_I_FRAME:
267  return read_frame(vid, pb, pkt, block_type, s);
268 
269  case EOF_BLOCK:
270  if(vid->nframes != 0)
271  av_log(s, AV_LOG_VERBOSE, "reached terminating character but not all frames read.\n");
272  vid->is_finished = 1;
273  return AVERROR(EIO);
274  default:
275  av_log(s, AV_LOG_ERROR, "unknown block (character = %c, decimal = %d, hex = %x)!!!\n",
276  block_type, block_type, block_type);
277  return AVERROR_INVALIDDATA;
278  }
279 }
280 
282 {
283  BVID_DemuxContext *vid = s->priv_data;
284  av_freep(&vid->palette);
285  return 0;
286 }
287 
289  .name = "bethsoftvid",
290  .long_name = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),
291  .priv_data_size = sizeof(BVID_DemuxContext),
296 };