FFmpeg
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 "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
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:339
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:4926
#define avpriv_request_sample(...)
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int size
Definition: avcodec.h:1481
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:246
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
static AVPacket pkt
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:788
Format I/O context.
Definition: avformat.h:1358
static int read_header(AVFormatContext *s)
Definition: filmstripdec.c:38
int width
Video only.
Definition: avcodec.h:4034
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:803
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4499
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1426
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:310
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1512
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
#define FFMAX(a, b)
Definition: common.h:94
packed RGBA 8:8:8:8, 32bpp, RGBARGBA...
Definition: pixfmt.h:93
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1486
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:282
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:260
#define RAND_TAG
Definition: filmstripdec.c:32
#define s(width, name)
Definition: cbs_vp9.c:257
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:881
#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:1400
AVInputFormat ff_filmstrip_demuxer
Definition: filmstripdec.c:107
#define flags(name, subs,...)
Definition: cbs_av1.c:561
Main libavformat public API header.
int64_t nb_frames
number of frames in this stream if known or 0
Definition: avformat.h:932
void * priv_data
Format private data.
Definition: avformat.h:1386
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1479
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:3972
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
This structure stores compressed data.
Definition: avcodec.h:1457