FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/mtv.c
Date: 2024-04-23 06:12:56
Exec Total Coverage
Lines: 70 92 76.1%
Functions: 3 3 100.0%
Branches: 32 64 50.0%

Line Branch Exec Source
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/intreadwrite.h"
28 #include "libavutil/mem.h"
29 #include "avformat.h"
30 #include "demux.h"
31 #include "internal.h"
32
33 #define MTV_ASUBCHUNK_DATA_SIZE 500
34 #define MTV_HEADER_SIZE 512
35 #define MTV_AUDIO_PADDING_SIZE 12
36 #define MTV_IMAGE_DEFAULT_BPP 16
37 #define MTV_AUDIO_SAMPLING_RATE 44100
38
39 typedef struct MTVDemuxContext {
40
41 unsigned int file_size; ///< filesize, not always right
42 unsigned int segments; ///< number of 512 byte segments
43 unsigned int audio_identifier; ///< 'MP3' on all files I have seen
44 unsigned int audio_br; ///< bitrate of audio channel (mp3)
45 unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
46 unsigned int img_bpp; ///< frame bits per pixel
47 unsigned int img_width;
48 unsigned int img_height;
49 unsigned int img_segment_size; ///< size of image segment
50 unsigned int video_fps;
51 unsigned int full_segment_size;
52
53 } MTVDemuxContext;
54
55 7125 static int mtv_probe(const AVProbeData *p)
56 {
57 /* we need at least 57 bytes from the header
58 * to try parsing all required fields
59 */
60
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7125 if (p->buf_size < 57)
61 3 return 0;
62
63 /* Magic is 'AMV' */
64
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7122 if (*p->buf != 'A' || *(p->buf + 1) != 'M' || *(p->buf + 2) != 'V')
65 7121 return 0;
66
67 /* Audio magic is always MP3 */
68
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1 if (p->buf[43] != 'M' || p->buf[44] != 'P' || p->buf[45] != '3')
69 return 0;
70
71 /* Check for nonzero in bpp and (width|height) header fields */
72
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1 if(!(p->buf[51] && AV_RL16(&p->buf[52]) | AV_RL16(&p->buf[54])))
73 return 0;
74
75 /* If width or height are 0 then imagesize header field should not */
76
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1 if(!AV_RL16(&p->buf[52]) || !AV_RL16(&p->buf[54]))
77 {
78 if(!!AV_RL16(&p->buf[56]))
79 return AVPROBE_SCORE_EXTENSION;
80 else
81 return 0;
82 }
83
84 /* Image bpp is not an absolutely required
85 * field as we latter claim it should be 16
86 * no matter what. All samples in the wild
87 * are RGB565/555.
88 */
89
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1 if(p->buf[51] != MTV_IMAGE_DEFAULT_BPP)
90 return AVPROBE_SCORE_EXTENSION / 2;
91
92 /* We had enough data to parse header values
93 * but we expect to be able to get 512 bytes
94 * of header to be sure.
95 */
96
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1 if (p->buf_size < MTV_HEADER_SIZE)
97 return AVPROBE_SCORE_EXTENSION;
98
99 1 return AVPROBE_SCORE_MAX;
100 }
101
102 1 static int mtv_read_header(AVFormatContext *s)
103 {
104 1 MTVDemuxContext *mtv = s->priv_data;
105 1 AVIOContext *pb = s->pb;
106 AVStream *st;
107 unsigned int audio_subsegments;
108
109 1 avio_skip(pb, 3);
110 1 mtv->file_size = avio_rl32(pb);
111 1 mtv->segments = avio_rl32(pb);
112 1 avio_skip(pb, 32);
113 1 mtv->audio_identifier = avio_rl24(pb);
114 1 mtv->audio_br = avio_rl16(pb);
115 1 mtv->img_colorfmt = avio_rl24(pb);
116 1 mtv->img_bpp = avio_r8(pb);
117 1 mtv->img_width = avio_rl16(pb);
118 1 mtv->img_height = avio_rl16(pb);
119 1 mtv->img_segment_size = avio_rl16(pb);
120
121 /* Assume 16bpp even if claimed otherwise.
122 * We know its going to be RGBG565/555 anyway
123 */
124
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1 if (mtv->img_bpp != MTV_IMAGE_DEFAULT_BPP) {
125 av_log (s, AV_LOG_WARNING, "Header claims %dbpp (!= 16). Ignoring\n",
126 mtv->img_bpp);
127 mtv->img_bpp = MTV_IMAGE_DEFAULT_BPP;
128 }
129
130 /* Calculate width and height if missing from header */
131
132
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1 if (!mtv->img_width && mtv->img_height > 0 && mtv->img_bpp >= 8)
133 mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3)
134 / mtv->img_height;
135
136
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1 if (!mtv->img_height && mtv->img_width > 0 && mtv->img_bpp >= 8)
137 mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3)
138 / mtv->img_width;
139
140
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1 if(!mtv->img_height || !mtv->img_width || !mtv->img_segment_size){
141 av_log(s, AV_LOG_ERROR, "width or height or segment_size is invalid and I cannot calculate them from other information\n");
142 return AVERROR_INVALIDDATA;
143 }
144
145 1 avio_skip(pb, 4);
146 1 audio_subsegments = avio_rl16(pb);
147
148
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1 if (audio_subsegments == 0) {
149 avpriv_request_sample(s, "MTV files without audio");
150 return AVERROR_PATCHWELCOME;
151 }
152
153 1 mtv->full_segment_size =
154 1 audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
155 1 mtv->img_segment_size;
156 1 mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments;
157
158 // FIXME Add sanity check here
159
160 // all systems go! init decoders
161
162 // video - raw rgb565
163
164 1 st = avformat_new_stream(s, NULL);
165
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1 if(!st)
166 return AVERROR(ENOMEM);
167
168 1 avpriv_set_pts_info(st, 64, 1, mtv->video_fps);
169 1 st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
170 1 st->codecpar->codec_id = AV_CODEC_ID_RAWVIDEO;
171 1 st->codecpar->format = AV_PIX_FMT_RGB565BE;
172 1 st->codecpar->width = mtv->img_width;
173 1 st->codecpar->height = mtv->img_height;
174 1 st->codecpar->extradata = av_strdup("BottomUp");
175
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1 if (!st->codecpar->extradata)
176 return AVERROR(ENOMEM);
177 1 st->codecpar->extradata_size = 9;
178
179 // audio - mp3
180
181 1 st = avformat_new_stream(s, NULL);
182
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1 if(!st)
183 return AVERROR(ENOMEM);
184
185 1 avpriv_set_pts_info(st, 64, 1, MTV_AUDIO_SAMPLING_RATE);
186 1 st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
187 1 st->codecpar->codec_id = AV_CODEC_ID_MP3;
188 1 st->codecpar->bit_rate = mtv->audio_br;
189 1 ffstream(st)->need_parsing = AVSTREAM_PARSE_FULL;
190
191 // Jump over header
192
193
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1 if(avio_seek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
194 return AVERROR(EIO);
195
196 1 return 0;
197
198 }
199
200 123 static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
201 {
202 123 MTVDemuxContext *mtv = s->priv_data;
203 123 AVIOContext *pb = s->pb;
204 int ret;
205
206
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123 if((avio_tell(pb) - ffformatcontext(s)->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
207 {
208 83 avio_skip(pb, MTV_AUDIO_PADDING_SIZE);
209
210 83 ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
211
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83 if(ret < 0)
212 3 return ret;
213
214 80 pkt->pos -= MTV_AUDIO_PADDING_SIZE;
215 80 pkt->stream_index = 1;
216
217 }else
218 {
219 40 ret = av_get_packet(pb, pkt, mtv->img_segment_size);
220
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40 if(ret < 0)
221 return ret;
222
223 40 pkt->stream_index = 0;
224 }
225
226 120 return ret;
227 }
228
229 const FFInputFormat ff_mtv_demuxer = {
230 .p.name = "mtv",
231 .p.long_name = NULL_IF_CONFIG_SMALL("MTV"),
232 .priv_data_size = sizeof(MTVDemuxContext),
233 .read_probe = mtv_probe,
234 .read_header = mtv_read_header,
235 .read_packet = mtv_read_packet,
236 };
237