FFmpeg  2.1.1
filmstripdec.c
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1 /*
2  * Adobe Filmstrip demuxer
3  * Copyright (c) 2010 Peter Ross
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  * Adobe Filmstrip demuxer
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "avformat.h"
29 #include "internal.h"
30 
31 #define RAND_TAG MKBETAG('R','a','n','d')
32 
33 typedef struct {
34  int leading;
36 
38 {
40  AVIOContext *pb = s->pb;
41  AVStream *st;
42 
43  if (!s->pb->seekable)
44  return AVERROR(EIO);
45 
46  avio_seek(pb, avio_size(pb) - 36, SEEK_SET);
47  if (avio_rb32(pb) != RAND_TAG) {
48  av_log(s, AV_LOG_ERROR, "magic number not found\n");
49  return AVERROR_INVALIDDATA;
50  }
51 
52  st = avformat_new_stream(s, NULL);
53  if (!st)
54  return AVERROR(ENOMEM);
55 
56  st->nb_frames = avio_rb32(pb);
57  if (avio_rb16(pb) != 0) {
58  avpriv_request_sample(s, "Unsupported packing method");
59  return AVERROR_PATCHWELCOME;
60  }
61 
62  avio_skip(pb, 2);
66  st->codec->codec_tag = 0; /* no fourcc */
67  st->codec->width = avio_rb16(pb);
68  st->codec->height = avio_rb16(pb);
69  film->leading = avio_rb16(pb);
70  avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
71 
72  avio_seek(pb, 0, SEEK_SET);
73 
74  return 0;
75 }
76 
78  AVPacket *pkt)
79 {
81  AVStream *st = s->streams[0];
82 
83  if (url_feof(s->pb))
84  return AVERROR(EIO);
85  pkt->dts = avio_tell(s->pb) / (st->codec->width * (st->codec->height + film->leading) * 4);
86  pkt->size = av_get_packet(s->pb, pkt, st->codec->width * st->codec->height * 4);
87  avio_skip(s->pb, st->codec->width * film->leading * 4);
88  if (pkt->size < 0)
89  return pkt->size;
90  pkt->flags |= AV_PKT_FLAG_KEY;
91  return 0;
92 }
93 
94 static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
95 {
96  AVStream *st = s->streams[stream_index];
97  if (avio_seek(s->pb, FFMAX(timestamp, 0) * st->codec->width * st->codec->height * 4, SEEK_SET) < 0)
98  return -1;
99  return 0;
100 }
101 
103  .name = "filmstrip",
104  .long_name = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
105  .priv_data_size = sizeof(FilmstripDemuxContext),
108  .read_seek = read_seek,
109  .extensions = "flm",
110 };
const char * s
Definition: avisynth_c.h:668
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_PATCHWELCOME
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:478
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:3922
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:261
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:686
int size
Definition: avcodec.h:1064
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1342
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:624
Format I/O context.
Definition: avformat.h:968
static int read_header(AVFormatContext *s)
Definition: filmstripdec.c:37
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:248
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:3348
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:200
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1113
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: avcodec.h:4147
void * priv_data
Format private data.
Definition: avformat.h:988
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:151
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1069
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:117
int width
picture width / height.
Definition: avcodec.h:1314
AVStream ** streams
Definition: avformat.h:1016
#define RAND_TAG
Definition: filmstripdec.c:31
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:199
static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: filmstripdec.c:94
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: filmstripdec.c:77
Stream structure.
Definition: avformat.h:667
enum AVMediaType codec_type
Definition: avcodec.h:1154
#define FFMAX(a, b)
Definition: avcodec.h:923
enum AVCodecID codec_id
Definition: avcodec.h:1157
unsigned int codec_tag
fourcc (LSB first, so &quot;ABCD&quot; -&gt; (&#39;D&#39;&lt;&lt;24) + (&#39;C&#39;&lt;&lt;16) + (&#39;B&#39;&lt;&lt;8) + &#39;A&#39;).
Definition: avcodec.h:1172
AVIOContext * pb
I/O context.
Definition: avformat.h:1001
AVInputFormat ff_filmstrip_demuxer
Definition: filmstripdec.c:102
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:256
static int flags
Definition: cpu.c:45
int url_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:280
Main libavformat public API header.
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:722
#define AVERROR_INVALIDDATA
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: avcodec.h:4563
#define AVERROR(e)
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:609
int64_t dts
Decompression timestamp in AVStream-&gt;time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1062
static AVPacket pkt
Definition: demuxing.c:52
This structure stores compressed data.
Definition: avcodec.h:1040