FFmpeg: libavformat/dxa.c Source File

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libavformat

dxa.c

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1 /*

2 * DXA 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 #include <inttypes.h>

24 #include "libavutil/intreadwrite.h"

25 #include "avformat.h"

26 #include "internal.h"

27 #include "riff.h"

29 #define DXA_EXTRA_SIZE 9

31 typedef struct DXAContext {

32 int frames;

33 int has_sound;

34 int bpc;

35 uint32_t bytes_left;

36 int64_t wavpos, vidpos;

37 int readvid;

38 }DXAContext;

40 static int dxa_probe(AVProbeData *p)

41 {

42 int w, h;

43 if (p->buf_size < 15)

44 return 0;

45 w = AV_RB16(p->buf + 11);

46 h = AV_RB16(p->buf + 13);

47 /* check file header */

48 if (p->buf[0] == 'D' && p->buf[1] == 'E' &&

49 p->buf[2] == 'X' && p->buf[3] == 'A' &&

50 w && w <= 2048 && h && h <= 2048)

51 return AVPROBE_SCORE_MAX;

52 else

53 return 0;

54 }

56 static int dxa_read_header(AVFormatContext *s)

57 {

58 AVIOContext *pb = s->pb;

59 DXAContext *c = s->priv_data;

60 AVStream *st, *ast;

61 uint32_t tag;

62 int32_t fps;

63 int w, h;

64 int num, den;

65 int flags;

66 int ret;

68 tag = avio_rl32(pb);

69 if (tag != MKTAG('D', 'E', 'X', 'A'))

70 return AVERROR_INVALIDDATA;

71 flags = avio_r8(pb);

72 c->frames = avio_rb16(pb);

73 if(!c->frames){

74 av_log(s, AV_LOG_ERROR, "File contains no frames ???\n");

75 return AVERROR_INVALIDDATA;

76 }

78 fps = avio_rb32(pb);

79 if(fps > 0){

80 den = 1000;

81 num = fps;

82 }else if (fps < 0){

83 den = 100000;

84 num = -fps;

85 }else{

86 den = 10;

87 num = 1;

88 }

89 w = avio_rb16(pb);

90 h = avio_rb16(pb);

91 c->has_sound = 0;

93 st = avformat_new_stream(s, NULL);

94 if (!st)

95 return AVERROR(ENOMEM);

97 // Parse WAV data header

98 if(avio_rl32(pb) == MKTAG('W', 'A', 'V', 'E')){

99 uint32_t size, fsize;

100 c->has_sound = 1;

101 size = avio_rb32(pb);

102 c->vidpos = avio_tell(pb) + size;

103 avio_skip(pb, 16);

104 fsize = avio_rl32(pb);

105

106 ast = avformat_new_stream(s, NULL);

107 if (!ast)

108 return AVERROR(ENOMEM);

109 ret = ff_get_wav_header(pb, ast->codec, fsize, 0);

110 if (ret < 0)

111 return ret;

112 if (ast->codec->sample_rate > 0)

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

114 // find 'data' chunk

115 while(avio_tell(pb) < c->vidpos && !avio_feof(pb)){

116 tag = avio_rl32(pb);

117 fsize = avio_rl32(pb);

118 if(tag == MKTAG('d', 'a', 't', 'a')) break;

119 avio_skip(pb, fsize);

120 }

121 c->bpc = (fsize + c->frames - 1) / c->frames;

122 if(ast->codec->block_align)

123 c->bpc = ((c->bpc + ast->codec->block_align - 1) / ast->codec->block_align) * ast->codec->block_align;

124 c->bytes_left = fsize;

125 c->wavpos = avio_tell(pb);

126 avio_seek(pb, c->vidpos, SEEK_SET);

127 }

128

129 /* now we are ready: build format streams */

130 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;

131 st->codec->codec_id = AV_CODEC_ID_DXA;

132 st->codec->width = w;

133 st->codec->height = h;

134 av_reduce(&den, &num, den, num, (1UL<<31)-1);

135 avpriv_set_pts_info(st, 33, num, den);

136 /* flags & 0x80 means that image is interlaced,

137 * flags & 0x40 means that image has double height

138 * either way set true height

139 */

140 if(flags & 0xC0){

141 st->codec->height >>= 1;

142 }

143 c->readvid = !c->has_sound;

144 c->vidpos = avio_tell(pb);

145 s->start_time = 0;

146 s->duration = (int64_t)c->frames * AV_TIME_BASE * num / den;

147 av_log(s, AV_LOG_DEBUG, "%d frame(s)\n",c->frames);

148

149 return 0;

150 }

151

152 static int dxa_read_packet(AVFormatContext *s, AVPacket *pkt)

153 {

154 DXAContext *c = s->priv_data;

155 int ret;

156 uint32_t size;

157 uint8_t buf[DXA_EXTRA_SIZE], pal[768+4];

158 int pal_size = 0;

159

160 if(!c->readvid && c->has_sound && c->bytes_left){

161 c->readvid = 1;

162 avio_seek(s->pb, c->wavpos, SEEK_SET);

163 size = FFMIN(c->bytes_left, c->bpc);

164 ret = av_get_packet(s->pb, pkt, size);

165 pkt->stream_index = 1;

166 if(ret != size)

167 return AVERROR(EIO);

168 c->bytes_left -= size;

169 c->wavpos = avio_tell(s->pb);

170 return 0;

171 }

172 avio_seek(s->pb, c->vidpos, SEEK_SET);

173 while(!avio_feof(s->pb) && c->frames){

174 if ((ret = avio_read(s->pb, buf, 4)) != 4) {

175 av_log(s, AV_LOG_ERROR, "failed reading chunk type\n");

176 return ret < 0 ? ret : AVERROR_INVALIDDATA;

177 }

178 switch(AV_RL32(buf)){

179 case MKTAG('N', 'U', 'L', 'L'):

180 if(av_new_packet(pkt, 4 + pal_size) < 0)

181 return AVERROR(ENOMEM);

182 pkt->stream_index = 0;

183 if(pal_size) memcpy(pkt->data, pal, pal_size);

184 memcpy(pkt->data + pal_size, buf, 4);

185 c->frames--;

186 c->vidpos = avio_tell(s->pb);

187 c->readvid = 0;

188 return 0;

189 case MKTAG('C', 'M', 'A', 'P'):

190 pal_size = 768+4;

191 memcpy(pal, buf, 4);

192 avio_read(s->pb, pal + 4, 768);

193 break;

194 case MKTAG('F', 'R', 'A', 'M'):

195 if ((ret = avio_read(s->pb, buf + 4, DXA_EXTRA_SIZE - 4)) != DXA_EXTRA_SIZE - 4) {

196 av_log(s, AV_LOG_ERROR, "failed reading dxa_extra\n");

197 return ret < 0 ? ret : AVERROR_INVALIDDATA;

198 }

199 size = AV_RB32(buf + 5);

200 if(size > 0xFFFFFF){

201 av_log(s, AV_LOG_ERROR, "Frame size is too big: %"PRIu32"\n",

202 size);

203 return AVERROR_INVALIDDATA;

204 }

205 if(av_new_packet(pkt, size + DXA_EXTRA_SIZE + pal_size) < 0)

206 return AVERROR(ENOMEM);

207 memcpy(pkt->data + pal_size, buf, DXA_EXTRA_SIZE);

208 ret = avio_read(s->pb, pkt->data + DXA_EXTRA_SIZE + pal_size, size);

209 if(ret != size){

210 av_free_packet(pkt);

211 return AVERROR(EIO);

212 }

213 if(pal_size) memcpy(pkt->data, pal, pal_size);

214 pkt->stream_index = 0;

215 c->frames--;

216 c->vidpos = avio_tell(s->pb);

217 c->readvid = 0;

218 return 0;

219 default:

220 av_log(s, AV_LOG_ERROR, "Unknown tag %c%c%c%c\n", buf[0], buf[1], buf[2], buf[3]);

221 return AVERROR_INVALIDDATA;

222 }

223 }

224 return AVERROR_EOF;

225 }

226

227 AVInputFormat ff_dxa_demuxer = {

228 .name = "dxa",

229 .long_name = NULL_IF_CONFIG_SMALL("DXA"),

230 .priv_data_size = sizeof(DXAContext),

231 .read_probe = dxa_probe,

232 .read_header = dxa_read_header,

233 .read_packet = dxa_read_packet,

234 };

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