FFmpeg: libavformat/jvdec.c Source File

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libavformat

jvdec.c

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1 /*

2 * Bitmap Brothers JV 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 * Bitmap Brothers JV demuxer

25 * @author Peter Ross <pross@xvid.org>

26 */

28 #include "libavutil/channel_layout.h"

29 #include "libavutil/intreadwrite.h"

30 #include "avformat.h"

31 #include "internal.h"

33 #define JV_PREAMBLE_SIZE 5

35 typedef struct {

36 int audio_size; /**< audio packet size (bytes) */

37 int video_size; /**< video packet size (bytes) */

38 int palette_size; /**< palette size (bytes) */

39 int video_type; /**< per-frame video compression type */

40 } JVFrame;

42 typedef struct {

43 JVFrame *frames;

44 enum {

45 JV_AUDIO = 0,

46 JV_VIDEO,

47 JV_PADDING

48 } state;

49 int64_t pts;

50 } JVDemuxContext;

54 static int read_probe(AVProbeData *pd)

55 {

56 if (pd->buf[0] == 'J' && pd->buf[1] == 'V' && strlen(MAGIC) <= pd->buf_size - 4 &&

57 !memcmp(pd->buf + 4, MAGIC, strlen(MAGIC)))

58 return AVPROBE_SCORE_MAX;

59 return 0;

60 }

62 static int read_header(AVFormatContext *s)

63 {

64 JVDemuxContext *jv = s->priv_data;

65 AVIOContext *pb = s->pb;

66 AVStream *vst, *ast;

67 int64_t audio_pts = 0;

68 int64_t offset;

69 int i;

71 avio_skip(pb, 80);

73 ast = avformat_new_stream(s, NULL);

74 vst = avformat_new_stream(s, NULL);

75 if (!ast || !vst)

76 return AVERROR(ENOMEM);

78 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

79 vst->codec->codec_id = AV_CODEC_ID_JV;

80 vst->codec->codec_tag = 0; /* no fourcc */

81 vst->codec->width = avio_rl16(pb);

82 vst->codec->height = avio_rl16(pb);

83 vst->duration =

84 vst->nb_frames =

85 ast->nb_index_entries = avio_rl16(pb);

86 avpriv_set_pts_info(vst, 64, avio_rl16(pb), 1000);

88 avio_skip(pb, 4);

90 ast->codec->codec_type = AVMEDIA_TYPE_AUDIO;

91 ast->codec->codec_id = AV_CODEC_ID_PCM_U8;

92 ast->codec->codec_tag = 0; /* no fourcc */

93 ast->codec->sample_rate = avio_rl16(pb);

94 ast->codec->channels = 1;

95 ast->codec->channel_layout = AV_CH_LAYOUT_MONO;

96 avpriv_set_pts_info(ast, 64, 1, ast->codec->sample_rate);

98 avio_skip(pb, 10);

100 ast->index_entries = av_malloc(ast->nb_index_entries * sizeof(*ast->index_entries));

101 if (!ast->index_entries)

102 return AVERROR(ENOMEM);

103

104 jv->frames = av_malloc(ast->nb_index_entries * sizeof(JVFrame));

105 if (!jv->frames)

106 return AVERROR(ENOMEM);

107

108 offset = 0x68 + ast->nb_index_entries * 16;

109 for(i = 0; i < ast->nb_index_entries; i++) {

110 AVIndexEntry *e = ast->index_entries + i;

111 JVFrame *jvf = jv->frames + i;

112

113 /* total frame size including audio, video, palette data and padding */

114 e->size = avio_rl32(pb);

115 e->timestamp = i;

116 e->pos = offset;

117 offset += e->size;

118

119 jvf->audio_size = avio_rl32(pb);

120 jvf->video_size = avio_rl32(pb);

121 jvf->palette_size = avio_r8(pb) ? 768 : 0;

122 jvf->video_size = FFMIN(FFMAX(jvf->video_size, 0),

123 INT_MAX - JV_PREAMBLE_SIZE - jvf->palette_size);

124 if (avio_r8(pb))

125 av_log(s, AV_LOG_WARNING, "unsupported audio codec\n");

126 jvf->video_type = avio_r8(pb);

127 avio_skip(pb, 1);

128

129 e->timestamp = jvf->audio_size ? audio_pts : AV_NOPTS_VALUE;

130 audio_pts += jvf->audio_size;

131

132 e->flags = jvf->video_type != 1 ? AVINDEX_KEYFRAME : 0;

133 }

134

135 jv->state = JV_AUDIO;

136 return 0;

137 }

138

139 static int read_packet(AVFormatContext *s, AVPacket *pkt)

140 {

141 JVDemuxContext *jv = s->priv_data;

142 AVIOContext *pb = s->pb;

143 AVStream *ast = s->streams[0];

144

145 while (!url_feof(s->pb) && jv->pts < ast->nb_index_entries) {

146 const AVIndexEntry *e = ast->index_entries + jv->pts;

147 const JVFrame *jvf = jv->frames + jv->pts;

148

149 switch(jv->state) {

150 case JV_AUDIO:

151 jv->state++;

152 if (jvf->audio_size ) {

153 if (av_get_packet(s->pb, pkt, jvf->audio_size) < 0)

154 return AVERROR(ENOMEM);

155 pkt->stream_index = 0;

156 pkt->pts = e->timestamp;

157 pkt->flags |= AV_PKT_FLAG_KEY;

158 return 0;

159 }

160 case JV_VIDEO:

161 jv->state++;

162 if (jvf->video_size || jvf->palette_size) {

163 int size = jvf->video_size + jvf->palette_size;

164 if (av_new_packet(pkt, size + JV_PREAMBLE_SIZE))

165 return AVERROR(ENOMEM);

166

167 AV_WL32(pkt->data, jvf->video_size);

168 pkt->data[4] = jvf->video_type;

169 if ((size = avio_read(pb, pkt->data + JV_PREAMBLE_SIZE, size)) < 0)

170 return AVERROR(EIO);

171

172 pkt->size = size + JV_PREAMBLE_SIZE;

173 pkt->stream_index = 1;

174 pkt->pts = jv->pts;

175 if (jvf->video_type != 1)

176 pkt->flags |= AV_PKT_FLAG_KEY;

177 return 0;

178 }

179 case JV_PADDING:

180 avio_skip(pb, FFMAX(e->size - jvf->audio_size - jvf->video_size

181 - jvf->palette_size, 0));

182 jv->state = JV_AUDIO;

183 jv->pts++;

184 }

185 }

186

187 return AVERROR(EIO);

188 }

189

190 static int read_seek(AVFormatContext *s, int stream_index,

191 int64_t ts, int flags)

192 {

193 JVDemuxContext *jv = s->priv_data;

194 AVStream *ast = s->streams[0];

195 int i;

196

197 if (flags & (AVSEEK_FLAG_BYTE|AVSEEK_FLAG_FRAME))

198 return AVERROR(ENOSYS);

199

200 switch(stream_index) {

201 case 0:

202 i = av_index_search_timestamp(ast, ts, flags);

203 break;

204 case 1:

205 i = ts;

206 break;

207 default:

208 return 0;

209 }

210

211 if (i < 0 || i >= ast->nb_index_entries)

212 return 0;

213 if (avio_seek(s->pb, ast->index_entries[i].pos, SEEK_SET) < 0)

214 return -1;

215

216 jv->state = JV_AUDIO;

217 jv->pts = i;

218 return 0;

219 }

220

221 static int read_close(AVFormatContext *s)

222 {

223 JVDemuxContext *jv = s->priv_data;

224

225 av_freep(&jv->frames);

226

227 return 0;

228 }

229

230 AVInputFormat ff_jv_demuxer = {

231 .name = "jv",

232 .long_name = NULL_IF_CONFIG_SMALL("Bitmap Brothers JV"),

233 .priv_data_size = sizeof(JVDemuxContext),

234 .read_probe = read_probe,

235 .read_header = read_header,

236 .read_packet = read_packet,

237 .read_seek = read_seek,

238 .read_close = read_close,

239 };

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