FFmpeg: libavformat/bethsoftvid.c Source File

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libavformat

bethsoftvid.c

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1 /*

2 * Bethsoft VID format Demuxer

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 */

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 */

30 #include "libavutil/channel_layout.h"

31 #include "libavutil/intreadwrite.h"

32 #include "avformat.h"

33 #include "internal.h"

34 #include "libavcodec/bethsoftvideo.h"

36 #define BVID_PALETTE_SIZE 3 * 256

38 #define DEFAULT_SAMPLE_RATE 11111

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) */

49 int bethsoft_global_delay;

50 int video_index; /**< video stream index */

51 int audio_index; /**< audio stream index */

52 uint8_t *palette;

54 int is_finished;

56 } BVID_DemuxContext;

58 static int vid_probe(AVProbeData *p)

59 {

60 // little-endian VID tag, file starts with "VID0円"

61 if (AV_RL32(p->buf) != MKTAG('V', 'I', 'D', 0))

62 return 0;

64 return AVPROBE_SCORE_MAX;

65 }

67 static int vid_read_header(AVFormatContext *s)

68 {

69 BVID_DemuxContext *vid = s->priv_data;

70 AVIOContext *pb = s->pb;

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);

80 vid->bethsoft_global_delay = avio_rl16(pb);

81 avio_rl16(pb);

83 // wait until the first packet to create each stream

84 vid->video_index = -1;

85 vid->audio_index = -1;

86 vid->sample_rate = DEFAULT_SAMPLE_RATE;

87 s->ctx_flags |= AVFMTCTX_NOHEADER;

89 return 0;

90 }

92 #define BUFFER_PADDING_SIZE 1000

93 static int read_frame(BVID_DemuxContext *vid, AVIOContext *pb, AVPacket *pkt,

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);

116 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

117 st->codec->codec_id = AV_CODEC_ID_BETHSOFTVID;

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) {

190 uint8_t *pdata = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE,

191 BVID_PALETTE_SIZE);

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

204 static int vid_read_packet(AVFormatContext *s,

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 }

223 vid->palette = av_malloc(BVID_PALETTE_SIZE);

224 if (!vid->palette)

225 return AVERROR(ENOMEM);

226 if (avio_read(pb, vid->palette, BVID_PALETTE_SIZE) != BVID_PALETTE_SIZE) {

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;

242 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;

243 st->codec->codec_id = AV_CODEC_ID_PCM_U8;

244 st->codec->channels = 1;

245 st->codec->channel_layout = AV_CH_LAYOUT_MONO;

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

281 static int vid_read_close(AVFormatContext *s)

282 {

283 BVID_DemuxContext *vid = s->priv_data;

284 av_freep(&vid->palette);

285 return 0;

286 }

287

288 AVInputFormat ff_bethsoftvid_demuxer = {

289 .name = "bethsoftvid",

290 .long_name = NULL_IF_CONFIG_SMALL("Bethesda Softworks VID"),

291 .priv_data_size = sizeof(BVID_DemuxContext),

292 .read_probe = vid_probe,

293 .read_header = vid_read_header,

294 .read_packet = vid_read_packet,

295 .read_close = vid_read_close,

296 };

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