FFmpeg: libavformat/hnm.c Source File

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libavformat

hnm.c

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1 /*

2 * Cryo Interactive Entertainment HNM4 demuxer

3 *

5 *

6 * This file is part of FFmpeg .

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg ; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 #include <inttypes.h>

25 #include "libavutil/intreadwrite.h"

26 #include "avformat.h"

27 #include "internal.h"

29 #define HNM4_TAG MKTAG('H', 'N', 'M', '4')

31 #define HNM4_SAMPLE_RATE 22050

32 #define HNM4_FRAME_FPS 24

34 #define HNM4_CHUNK_ID_PL 19536

35 #define HNM4_CHUNK_ID_IZ 23113

36 #define HNM4_CHUNK_ID_IU 21833

37 #define HNM4_CHUNK_ID_SD 17491

39 typedef struct Hnm4DemuxContext {

40 uint8_t version;

41 uint16_t width;

42 uint16_t height;

43 uint32_t filesize;

44 uint32_t frames;

45 uint32_t taboffset;

46 uint16_t bits;

47 uint16_t channels;

48 uint32_t framesize;

49 uint32_t currentframe;

50 int64_t pts;

51 uint32_t superchunk_remaining;

52 AVPacket vpkt;

53 } Hnm4DemuxContext;

55 static int hnm_probe(AVProbeData *p)

56 {

57 if (p->buf_size < 4)

58 return 0;

60 // check for HNM4 header.

61 // currently only HNM v4/v4A is supported

62 if (AV_RL32(&p->buf[0]) == HNM4_TAG)

63 return AVPROBE_SCORE_MAX;

65 return 0;

66 }

68 static int hnm_read_header(AVFormatContext *s)

69 {

70 Hnm4DemuxContext *hnm = s->priv_data;

71 AVIOContext *pb = s->pb;

72 AVStream *vst;

74 /* default context members */

75 hnm->pts = 0;

76 av_init_packet(&hnm->vpkt);

77 hnm->vpkt.data = NULL;

78 hnm->vpkt.size = 0;

80 hnm->superchunk_remaining = 0;

82 avio_skip(pb, 8);

83 hnm->width = avio_rl16(pb);

84 hnm->height = avio_rl16(pb);

85 hnm->filesize = avio_rl32(pb);

86 hnm->frames = avio_rl32(pb);

87 hnm->taboffset = avio_rl32(pb);

88 hnm->bits = avio_rl16(pb);

89 hnm->channels = avio_rl16(pb);

90 hnm->framesize = avio_rl32(pb);

91 avio_skip(pb, 32);

93 hnm->currentframe = 0;

95 if (hnm->width < 256 || hnm->width > 640 ||

96 hnm->height < 150 || hnm->height > 480) {

97 av_log(s, AV_LOG_ERROR,

98 "invalid resolution: %ux%u\n", hnm->width, hnm->height);

99 return AVERROR_INVALIDDATA;

100 }

101

102 // TODO: find a better way to detect HNM4A

103 if (hnm->width == 640)

104 hnm->version = 0x4a;

105 else

106 hnm->version = 0x40;

107

108 if (!(vst = avformat_new_stream(s, NULL)))

109 return AVERROR(ENOMEM);

110

111 vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;

112 vst->codec->codec_id = AV_CODEC_ID_HNM4_VIDEO;

113 vst->codec->codec_tag = 0;

114 vst->codec->width = hnm->width;

115 vst->codec->height = hnm->height;

116 vst->codec->extradata = av_mallocz(1);

117

118 vst->codec->extradata_size = 1;

119 memcpy(vst->codec->extradata, &hnm->version, 1);

120

121 vst->start_time = 0;

122

123 avpriv_set_pts_info(vst, 33, 1, HNM4_FRAME_FPS);

124

125 return 0;

126 }

127

128 static int hnm_read_packet(AVFormatContext *s, AVPacket *pkt)

129 {

130 Hnm4DemuxContext *hnm = s->priv_data;

131 AVIOContext *pb = s->pb;

132 int ret = 0;

133

134 uint32_t superchunk_size, chunk_size;

135 uint16_t chunk_id;

136

137 if (hnm->currentframe == hnm->frames || pb->eof_reached)

138 return AVERROR_EOF;

139

140 if (hnm->superchunk_remaining == 0) {

141 /* parse next superchunk */

142 superchunk_size = avio_rl24(pb);

143 avio_skip(pb, 1);

144

145 hnm->superchunk_remaining = superchunk_size - 4;

146 }

147

148 chunk_size = avio_rl24(pb);

149 avio_skip(pb, 1);

150 chunk_id = avio_rl16(pb);

151 avio_skip(pb, 2);

152

153 if (chunk_size > hnm->superchunk_remaining || !chunk_size) {

154 av_log(s, AV_LOG_ERROR,

155 "invalid chunk size: %"PRIu32", offset: %"PRId64"\n",

156 chunk_size, avio_tell(pb));

157 avio_skip(pb, hnm->superchunk_remaining - 8);

158 hnm->superchunk_remaining = 0;

159 }

160

161 switch (chunk_id) {

162 case HNM4_CHUNK_ID_PL:

163 case HNM4_CHUNK_ID_IZ:

164 case HNM4_CHUNK_ID_IU:

165 avio_seek(pb, -8, SEEK_CUR);

166 ret += av_get_packet(pb, pkt, chunk_size);

167 hnm->superchunk_remaining -= chunk_size;

168 if (chunk_id == HNM4_CHUNK_ID_IZ || chunk_id == HNM4_CHUNK_ID_IU)

169 hnm->currentframe++;

170 break;

171

172 case HNM4_CHUNK_ID_SD:

173 avio_skip(pb, chunk_size - 8);

174 hnm->superchunk_remaining -= chunk_size;

175 break;

176

177 default:

178 av_log(s, AV_LOG_WARNING, "unknown chunk found: %"PRIu16", offset: %"PRId64"\n",

179 chunk_id, avio_tell(pb));

180 avio_skip(pb, chunk_size - 8);

181 hnm->superchunk_remaining -= chunk_size;

182 break;

183 }

184

185 return ret;

186 }

187

188 static int hnm_read_close(AVFormatContext *s)

189 {

190 Hnm4DemuxContext *hnm = s->priv_data;

191

192 if (hnm->vpkt.size > 0)

193 av_free_packet(&hnm->vpkt);

194

195 return 0;

196 }

197

198 AVInputFormat ff_hnm_demuxer = {

199 .name = "hnm",

200 .long_name = NULL_IF_CONFIG_SMALL("Cryo HNM v4"),

201 .priv_data_size = sizeof(Hnm4DemuxContext),

202 .read_probe = hnm_probe,

203 .read_header = hnm_read_header,

204 .read_packet = hnm_read_packet,

205 .read_close = hnm_read_close,

206 .flags = AVFMT_NO_BYTE_SEEK | AVFMT_NOGENSEARCH | AVFMT_NOBINSEARCH

207 };

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