FFmpeg: libavformat/supenc.c Source File

FFmpeg
supenc.c
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1 /*
2  * SUP muxer
3  * Copyright (c) 2014 Petri Hintukainen <phintuka@users.sourceforge.net>
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 #include "avformat.h"
23 #include "internal.h"
24 #include "libavutil/intreadwrite.h"
25 
26  #define SUP_PGS_MAGIC 0x5047 /* "PG", big endian */
27 
28  static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
29 {
30  const uint8_t *data = pkt->data;
31  size_t size = pkt->size;
32  uint32_t pts = 0, dts = 0;
33 
34  if (pkt->pts != AV_NOPTS_VALUE) {
35  pts = pkt->pts;
36  }
37  if (pkt->dts != AV_NOPTS_VALUE) {
38  dts = pkt->dts;
39  }
40 
41  /*
42  Split frame to segments.
43  mkvmerge stores multiple segments in one frame.
44  */
45  while (size > 2) {
46  size_t len = AV_RB16(data + 1) + 3;
47 
48  if (len > size) {
49  av_log(s, AV_LOG_ERROR, "Not enough data, skipping %"SIZE_SPECIFIER " bytes\n",
50  size);
51  return AVERROR_INVALIDDATA;
52  }
53 
54  /* header */
55  avio_wb16(s->pb, SUP_PGS_MAGIC);
56  avio_wb32(s->pb, pts);
57  avio_wb32(s->pb, dts);
58 
59  avio_write(s->pb, data, len);
60 
61  data += len;
62  size -= len;
63  }
64 
65  if (size > 0) {
66  av_log(s, AV_LOG_ERROR, "Skipping %"SIZE_SPECIFIER " bytes after last segment in frame\n",
67  size);
68  return AVERROR_INVALIDDATA;
69  }
70 
71  return 0;
72 }
73 
74  static int sup_write_header(AVFormatContext *s)
75 {
76  if (s->nb_streams != 1) {
77  av_log(s, AV_LOG_ERROR, "%s files have exactly one stream\n",
78  s->oformat->name);
79  return AVERROR(EINVAL);
80  }
81 
82  avpriv_set_pts_info(s->streams[0], 32, 1, 90000);
83 
84  return 0;
85 }
86 
87  const AVOutputFormat ff_sup_muxer = {
88  .name = "sup",
89  .long_name = NULL_IF_CONFIG_SMALL("raw HDMV Presentation Graphic Stream subtitles"),
90  .extensions = "sup",
91  .mime_type = "application/x-pgs",
92  .subtitle_codec = AV_CODEC_ID_HDMV_PGS_SUBTITLE,
93  .write_header = sup_write_header,
94  .write_packet = sup_write_packet,
95  .flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
96 };
AVOutputFormat::name
const char * name
Definition: avformat.h:510
AVERROR
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
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:484
AVPacket::data
uint8_t * data
Definition: packet.h:374
data
const char data[16]
Definition: mxf.c:143
AV_CODEC_ID_HDMV_PGS_SUBTITLE
@ AV_CODEC_ID_HDMV_PGS_SUBTITLE
Definition: codec_id.h:533
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:697
pts
static int64_t pts
Definition: transcode_aac.c:654
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVFormatContext
Format I/O context.
Definition: avformat.h:1213
internal.h
AVPacket::size
int size
Definition: packet.h:375
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
SUP_PGS_MAGIC
#define SUP_PGS_MAGIC
Definition: supenc.c:26
size
int size
Definition: twinvq_data.h:10344
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
ff_sup_muxer
const AVOutputFormat ff_sup_muxer
Definition: supenc.c:87
AVPacket::dts
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:373
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:232
avio_wb32
void avio_wb32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:394
AVOutputFormat
Definition: avformat.h:509
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
len
int len
Definition: vorbis_enc_data.h:426
AVFMT_TS_NONSTRICT
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:491
sup_write_header
static int sup_write_header(AVFormatContext *s)
Definition: supenc.c:74
avformat.h
SIZE_SPECIFIER
#define SIZE_SPECIFIER
Definition: internal.h:195
sup_write_packet
static int sup_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: supenc.c:28
AVPacket
This structure stores compressed data.
Definition: packet.h:351
avio_wb16
void avio_wb16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:472
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98
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