FFmpeg: libavformat/tmv.c Source File
Go to the documentation of this file. 1 /*
2 * 8088flex TMV file demuxer
3 * Copyright (c) 2009 Daniel Verkamp <daniel at drv.nu>
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 * 8088flex TMV file demuxer
25 * @author Daniel Verkamp
26 * @see http://www.oldskool.org/pc/8088_Corruption
27 */
28
34
35 enum {
38 };
39
40 #define TMV_TAG MKTAG('T', 'M', 'A', 'V')
41
48
49 #define TMV_HEADER_SIZE 12
50
51 #define PROBE_MIN_SAMPLE_RATE 5000
52 #define PROBE_MAX_FPS 120
53 #define PROBE_MIN_AUDIO_SIZE (PROBE_MIN_SAMPLE_RATE / PROBE_MAX_FPS)
54
56 {
60 !p->
buf[8] &&
// compression method
61 p->
buf[9] &&
// char cols
62 p->
buf[10])
// char rows
64 ((p->
buf[9] == 40 && p->
buf[10] == 25) ? 1 : 4);
65 return 0;
66 }
67
69 {
74 unsigned comp_method, char_cols, char_rows, features;
75
77 return -1;
78
81
84
88 return -1;
89 }
90
94 return -1;
95 }
96
98 if (comp_method) {
100 comp_method);
101 return -1;
102 }
103
110 }
111
116 return -1;
117 }
118
126
130
137
142
145
146 return 0;
147 }
148
150 {
155
158
160
163
167
169 }
170
173 {
176
177 if (stream_index)
178 return -1;
179
182
184 return -1;
186 return 0;
187 }
188
198 };
Filter the word "frame" indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
enum AVMediaType codec_type
General type of the encoded data.
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
#define AVERROR_EOF
End of file.
int nb_channels
Number of channels in this layout.
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
static int read_seek(AVFormatContext *ctx, int stream_index, int64_t timestamp, int flags)
int av_reduce(int *dst_num, int *dst_den, int64_t num, int64_t den, int64_t max)
Reduce a fraction.
unsigned int avio_rl16(AVIOContext *s)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
unsigned video_chunk_size
AVCodecParameters * codecpar
Codec parameters associated with this stream.
static int read_header(FFV1Context *f)
Rational number (pair of numerator and denominator).
This structure contains the data a format has to probe a file.
AVChannelLayout ch_layout
Audio only.
int sample_rate
Audio only.
unsigned int avio_rl32(AVIOContext *s)
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
int avio_r8(AVIOContext *s)
int flags
A combination of AV_PKT_FLAG values.
void av_channel_layout_default(AVChannelLayout *ch_layout, int nb_channels)
Get the default channel layout for a given number of channels.
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
static int read_probe(const AVProbeData *p)
int bits_per_coded_sample
The number of bits per sample in the codedwords.
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
This structure stores compressed data.
#define flags(name, subs,...)
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
unsigned audio_chunk_size
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
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