FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
filmstripdec.c
Go to the documentation of this file.
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 "libavutil/imgutils.h"
29 #include "avformat.h"
30 #include "internal.h"
31 
32 #define RAND_TAG MKBETAG('R','a','n','d')
33 
34 typedef struct FilmstripDemuxContext {
35  int leading;
37 
39 {
41  AVIOContext *pb = s->pb;
42  AVStream *st;
43 
44  if (!(s->pb->seekable & AVIO_SEEKABLE_NORMAL))
45  return AVERROR(EIO);
46 
47  avio_seek(pb, avio_size(pb) - 36, SEEK_SET);
48  if (avio_rb32(pb) != RAND_TAG) {
49  av_log(s, AV_LOG_ERROR, "magic number not found\n");
50  return AVERROR_INVALIDDATA;
51  }
52 
53  st = avformat_new_stream(s, NULL);
54  if (!st)
55  return AVERROR(ENOMEM);
56 
57  st->nb_frames = avio_rb32(pb);
58  if (avio_rb16(pb) != 0) {
59  avpriv_request_sample(s, "Unsupported packing method");
60  return AVERROR_PATCHWELCOME;
61  }
62 
63  avio_skip(pb, 2);
67  st->codecpar->codec_tag = 0; /* no fourcc */
68  st->codecpar->width = avio_rb16(pb);
69  st->codecpar->height = avio_rb16(pb);
70  film->leading = avio_rb16(pb);
71 
72  if (av_image_check_size(st->codecpar->width, st->codecpar->height, 0, s) < 0)
73  return AVERROR_INVALIDDATA;
74 
75  avpriv_set_pts_info(st, 64, 1, avio_rb16(pb));
76 
77  avio_seek(pb, 0, SEEK_SET);
78 
79  return 0;
80 }
81 
83  AVPacket *pkt)
84 {
86  AVStream *st = s->streams[0];
87 
88  if (avio_feof(s->pb))
89  return AVERROR(EIO);
90  pkt->dts = avio_tell(s->pb) / (st->codecpar->width * (int64_t)(st->codecpar->height + film->leading) * 4);
91  pkt->size = av_get_packet(s->pb, pkt, st->codecpar->width * st->codecpar->height * 4);
92  avio_skip(s->pb, st->codecpar->width * (int64_t) film->leading * 4);
93  if (pkt->size < 0)
94  return pkt->size;
95  pkt->flags |= AV_PKT_FLAG_KEY;
96  return 0;
97 }
98 
99 static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
100 {
101  AVStream *st = s->streams[stream_index];
102  if (avio_seek(s->pb, FFMAX(timestamp, 0) * st->codecpar->width * st->codecpar->height * 4, SEEK_SET) < 0)
103  return -1;
104  return 0;
105 }
106 
108  .name = "filmstrip",
109  .long_name = NULL_IF_CONFIG_SMALL("Adobe Filmstrip"),
110  .priv_data_size = sizeof(FilmstripDemuxContext),
113  .read_seek = read_seek,
114  .extensions = "flm",
115 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:334
misc image utilities
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:4737
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4152
int size
Definition: avcodec.h:1680
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:244
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:329
static AVPacket pkt
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:775
Format I/O context.
Definition: avformat.h:1349
static int read_header(AVFormatContext *s)
Definition: filmstripdec.c:38
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
int width
Video only.
Definition: avcodec.h:4218
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:790
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4367
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1417
static int flags
Definition: log.c:57
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:289
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:556
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1711
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:179
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:4148
#define FFMAX(a, b)
Definition: common.h:94
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:94
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1685
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:281
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:261
#define RAND_TAG
Definition: filmstripdec.c:32
static int read_seek(AVFormatContext *s, int stream_index, int64_t timestamp, int flags)
Definition: filmstripdec.c:99
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: filmstripdec.c:82
Stream structure.
Definition: avformat.h:889
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
AVIOContext * pb
I/O context.
Definition: avformat.h:1391
AVInputFormat ff_filmstrip_demuxer
Definition: filmstripdec.c:107
Main libavformat public API header.
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:948
void * priv_data
Format private data.
Definition: avformat.h:1377
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1678
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVCodecParameters * codecpar
Definition: avformat.h:1252
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:356
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:4156
This structure stores compressed data.
Definition: avcodec.h:1656