blob: dcf4aa428807203440f2d0761e8d9494bca67adf
1 | /* |
2 | * mtv demuxer |
3 | * Copyright (c) 2006 Reynaldo H. Verdejo Pinochet |
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 | * MTV demuxer. |
25 | */ |
26 | |
27 | #include "libavutil/bswap.h" |
28 | #include "libavutil/intreadwrite.h" |
29 | #include "avformat.h" |
30 | #include "internal.h" |
31 | |
32 | #define MTV_ASUBCHUNK_DATA_SIZE 500 |
33 | #define MTV_HEADER_SIZE 512 |
34 | #define MTV_AUDIO_PADDING_SIZE 12 |
35 | #define MTV_IMAGE_DEFAULT_BPP 16 |
36 | #define MTV_AUDIO_SAMPLING_RATE 44100 |
37 | |
38 | typedef struct MTVDemuxContext { |
39 | |
40 | unsigned int file_size; ///< filesize, not always right |
41 | unsigned int segments; ///< number of 512 byte segments |
42 | unsigned int audio_identifier; ///< 'MP3' on all files I have seen |
43 | unsigned int audio_br; ///< bitrate of audio channel (mp3) |
44 | unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555 |
45 | unsigned int img_bpp; ///< frame bits per pixel |
46 | unsigned int img_width; |
47 | unsigned int img_height; |
48 | unsigned int img_segment_size; ///< size of image segment |
49 | unsigned int video_fps; |
50 | unsigned int full_segment_size; |
51 | |
52 | } MTVDemuxContext; |
53 | |
54 | static int mtv_probe(AVProbeData *p) |
55 | { |
56 | /* we need at least 57 bytes from the header |
57 | * to try parsing all required fields |
58 | */ |
59 | if (p->buf_size < 57) |
60 | return 0; |
61 | |
62 | /* Magic is 'AMV' */ |
63 | if (*p->buf != 'A' || *(p->buf + 1) != 'M' || *(p->buf + 2) != 'V') |
64 | return 0; |
65 | |
66 | /* Audio magic is always MP3 */ |
67 | if (p->buf[43] != 'M' || p->buf[44] != 'P' || p->buf[45] != '3') |
68 | return 0; |
69 | |
70 | /* Check for nonzero in bpp and (width|height) header fields */ |
71 | if(!(p->buf[51] && AV_RL16(&p->buf[52]) | AV_RL16(&p->buf[54]))) |
72 | return 0; |
73 | |
74 | /* If width or height are 0 then imagesize header field should not */ |
75 | if(!AV_RL16(&p->buf[52]) || !AV_RL16(&p->buf[54])) |
76 | { |
77 | if(!!AV_RL16(&p->buf[56])) |
78 | return AVPROBE_SCORE_EXTENSION; |
79 | else |
80 | return 0; |
81 | } |
82 | |
83 | /* Image bpp is not an absolutely required |
84 | * field as we latter claim it should be 16 |
85 | * no matter what. All samples in the wild |
86 | * are RGB565/555. |
87 | */ |
88 | if(p->buf[51] != MTV_IMAGE_DEFAULT_BPP) |
89 | return AVPROBE_SCORE_EXTENSION / 2; |
90 | |
91 | /* We had enough data to parse header values |
92 | * but we expect to be able to get 512 bytes |
93 | * of header to be sure. |
94 | */ |
95 | if (p->buf_size < MTV_HEADER_SIZE) |
96 | return AVPROBE_SCORE_EXTENSION; |
97 | |
98 | return AVPROBE_SCORE_MAX; |
99 | } |
100 | |
101 | static int mtv_read_header(AVFormatContext *s) |
102 | { |
103 | MTVDemuxContext *mtv = s->priv_data; |
104 | AVIOContext *pb = s->pb; |
105 | AVStream *st; |
106 | unsigned int audio_subsegments; |
107 | |
108 | avio_skip(pb, 3); |
109 | mtv->file_size = avio_rl32(pb); |
110 | mtv->segments = avio_rl32(pb); |
111 | avio_skip(pb, 32); |
112 | mtv->audio_identifier = avio_rl24(pb); |
113 | mtv->audio_br = avio_rl16(pb); |
114 | mtv->img_colorfmt = avio_rl24(pb); |
115 | mtv->img_bpp = avio_r8(pb); |
116 | mtv->img_width = avio_rl16(pb); |
117 | mtv->img_height = avio_rl16(pb); |
118 | mtv->img_segment_size = avio_rl16(pb); |
119 | |
120 | /* Assume 16bpp even if claimed otherwise. |
121 | * We know its going to be RGBG565/555 anyway |
122 | */ |
123 | if (mtv->img_bpp != MTV_IMAGE_DEFAULT_BPP) { |
124 | av_log (s, AV_LOG_WARNING, "Header claims %dbpp (!= 16). Ignoring\n", |
125 | mtv->img_bpp); |
126 | mtv->img_bpp = MTV_IMAGE_DEFAULT_BPP; |
127 | } |
128 | |
129 | /* Calculate width and height if missing from header */ |
130 | |
131 | if (!mtv->img_width && mtv->img_height > 0 && mtv->img_bpp >= 8) |
132 | mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3) |
133 | / mtv->img_height; |
134 | |
135 | if (!mtv->img_height && mtv->img_width > 0 && mtv->img_bpp >= 8) |
136 | mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3) |
137 | / mtv->img_width; |
138 | |
139 | if(!mtv->img_height || !mtv->img_width || !mtv->img_segment_size){ |
140 | av_log(s, AV_LOG_ERROR, "width or height or segment_size is invalid and I cannot calculate them from other information\n"); |
141 | return AVERROR_INVALIDDATA; |
142 | } |
143 | |
144 | avio_skip(pb, 4); |
145 | audio_subsegments = avio_rl16(pb); |
146 | |
147 | if (audio_subsegments == 0) { |
148 | avpriv_request_sample(s, "MTV files without audio"); |
149 | return AVERROR_PATCHWELCOME; |
150 | } |
151 | |
152 | mtv->full_segment_size = |
153 | audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) + |
154 | mtv->img_segment_size; |
155 | mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments; |
156 | |
157 | // FIXME Add sanity check here |
158 | |
159 | // all systems go! init decoders |
160 | |
161 | // video - raw rgb565 |
162 | |
163 | st = avformat_new_stream(s, NULL); |
164 | if(!st) |
165 | return AVERROR(ENOMEM); |
166 | |
167 | avpriv_set_pts_info(st, 64, 1, mtv->video_fps); |
168 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
169 | st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO; |
170 | st->codecpar->format = AV_PIX_FMT_RGB565BE; |
171 | st->codecpar->width = mtv->img_width; |
172 | st->codecpar->height = mtv->img_height; |
173 | st->codecpar->extradata = av_strdup("BottomUp"); |
174 | st->codecpar->extradata_size = 9; |
175 | |
176 | // audio - mp3 |
177 | |
178 | st = avformat_new_stream(s, NULL); |
179 | if(!st) |
180 | return AVERROR(ENOMEM); |
181 | |
182 | avpriv_set_pts_info(st, 64, 1, MTV_AUDIO_SAMPLING_RATE); |
183 | st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO; |
184 | st->codecpar->codec_id = AV_CODEC_ID_MP3; |
185 | st->codecpar->bit_rate = mtv->audio_br; |
186 | st->need_parsing = AVSTREAM_PARSE_FULL; |
187 | |
188 | // Jump over header |
189 | |
190 | if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE) |
191 | return AVERROR(EIO); |
192 | |
193 | return 0; |
194 | |
195 | } |
196 | |
197 | static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt) |
198 | { |
199 | MTVDemuxContext *mtv = s->priv_data; |
200 | AVIOContext *pb = s->pb; |
201 | int ret; |
202 | |
203 | if((avio_tell(pb) - s->internal->data_offset + mtv->img_segment_size) % mtv->full_segment_size) |
204 | { |
205 | avio_skip(pb, MTV_AUDIO_PADDING_SIZE); |
206 | |
207 | ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE); |
208 | if(ret < 0) |
209 | return ret; |
210 | |
211 | pkt->pos -= MTV_AUDIO_PADDING_SIZE; |
212 | pkt->stream_index = 1; |
213 | |
214 | }else |
215 | { |
216 | ret = av_get_packet(pb, pkt, mtv->img_segment_size); |
217 | if(ret < 0) |
218 | return ret; |
219 | |
220 | pkt->stream_index = 0; |
221 | } |
222 | |
223 | return ret; |
224 | } |
225 | |
226 | AVInputFormat ff_mtv_demuxer = { |
227 | .name = "mtv", |
228 | .long_name = NULL_IF_CONFIG_SMALL("MTV"), |
229 | .priv_data_size = sizeof(MTVDemuxContext), |
230 | .read_probe = mtv_probe, |
231 | .read_header = mtv_read_header, |
232 | .read_packet = mtv_read_packet, |
233 | }; |
234 |