FFmpeg: libavformat/sccenc.c Source File

FFmpeg
sccenc.c
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1 /*
2  * SCC muxer
3  * Copyright (c) 2017 Paul B Mahol
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/log.h"
25 #include "libavutil/intreadwrite.h"
26 
27 typedef struct SCCContext {
28   int prev_h, prev_m, prev_s, prev_f;
29   int inside;
30   int n;
31 } SCCContext;
32 
33  static int scc_write_header(AVFormatContext *avf)
34 {
35  SCCContext *scc = avf->priv_data;
36 
37  if (avf->nb_streams != 1 ||
38  avf->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_SUBTITLE) {
39  av_log(avf, AV_LOG_ERROR,
40  "SCC supports only a single subtitles stream.\n");
41  return AVERROR(EINVAL);
42  }
43  if (avf->streams[0]->codecpar->codec_id != AV_CODEC_ID_EIA_608) {
44  av_log(avf, AV_LOG_ERROR,
45  "Unsupported subtitles codec: %s\n",
46  avcodec_get_name(avf->streams[0]->codecpar->codec_id));
47  return AVERROR(EINVAL);
48  }
49  avpriv_set_pts_info(avf->streams[0], 64, 1, 1000);
50  avio_printf(avf->pb, "Scenarist_SCC V1.0\n");
51 
52  scc->prev_h = scc->prev_m = scc->prev_s = scc->prev_f = -1;
53  scc->inside = 0;
54 
55  return 0;
56 }
57 
58  static int scc_write_packet(AVFormatContext *avf, AVPacket *pkt)
59 {
60  SCCContext *scc = avf->priv_data;
61  int64_t pts = pkt->pts;
62  int i, h, m, s, f;
63 
64  if (pts == AV_NOPTS_VALUE) {
65  av_log(avf, AV_LOG_WARNING,
66  "Insufficient timestamps.\n");
67  return 0;
68  }
69 
70  h = (int)(pts / (3600000));
71  m = (int)(pts / (60000)) % 60;
72  s = (int)(pts / 1000) % 60;
73  f = (int)(pts % 1000) / 33;
74 
75  for (i = 0; i < pkt->size; i+=3) {
76  if (pkt->data[i] == 0xfc && ((pkt->data[i + 1] != 0x80 || pkt->data[i + 2] != 0x80)))
77  break;
78  }
79  if (i >= pkt->size)
80  return 0;
81 
82  if (!scc->inside && (scc->prev_h != h || scc->prev_m != m || scc->prev_s != s || scc->prev_f != f)) {
83  avio_printf(avf->pb, "\n%02d:%02d:%02d:%02d\t", h, m, s, f);
84  scc->inside = 1;
85  }
86  for (i = 0; i < pkt->size; i+=3) {
87  if (i + 3 > pkt->size)
88  break;
89 
90  if (pkt->data[i] != 0xfc || (pkt->data[i + 1] == 0x80 && pkt->data[i + 2] == 0x80))
91  continue;
92  if (!scc->inside) {
93  avio_printf(avf->pb, "\n%02d:%02d:%02d:%02d\t", h, m, s, f);
94  scc->inside = 1;
95  }
96  if (scc->n > 0)
97  avio_printf(avf->pb, " ");
98  avio_printf(avf->pb, "%02x%02x", pkt->data[i + 1], pkt->data[i + 2]);
99  scc->n++;
100  }
101  if (scc->inside && (scc->prev_h != h || scc->prev_m != m || scc->prev_s != s || scc->prev_f != f)) {
102  avio_printf(avf->pb, "\n");
103  scc->n = 0;
104  scc->inside = 0;
105  }
106 
107  scc->prev_h = h;
108  scc->prev_m = m;
109  scc->prev_s = s;
110  scc->prev_f = f;
111  return 0;
112 }
113 
114  AVOutputFormat ff_scc_muxer = {
115  .name = "scc",
116  .long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"),
117  .extensions = "scc",
118  .priv_data_size = sizeof(SCCContext),
119  .write_header = scc_write_header,
120  .write_packet = scc_write_packet,
121  .flags = AVFMT_GLOBALHEADER | AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT,
122  .subtitle_codec = AV_CODEC_ID_EIA_608,
123 };
write_packet
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost, int unqueue)
Definition: ffmpeg.c:679
s
const char * s
Definition: avisynth_c.h:768
h
h
Definition: vp9dsp_template.c:2038
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
avpriv_set_pts_info
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:4820
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3884
AVPacket::size
int size
Definition: avcodec.h:1431
SCCContext::prev_f
int prev_f
Definition: sccenc.c:28
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
AV_CODEC_ID_EIA_608
Definition: avcodec.h:654
AVFMT_TS_NONSTRICT
#define AVFMT_TS_NONSTRICT
Format does not require strictly increasing timestamps, but they must still be monotonic.
Definition: avformat.h:479
AVFormatContext
Format I/O context.
Definition: avformat.h:1342
scc_write_header
static int scc_write_header(AVFormatContext *avf)
Definition: sccenc.c:33
SCCContext::prev_m
int prev_m
Definition: sccenc.c:28
SCCContext
Definition: sccdec.c:28
AVFormatContext::streams
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1410
AVPacket::data
uint8_t * data
Definition: avcodec.h:1430
flags
static int flags
Definition: log.c:55
SCCContext::inside
int inside
Definition: sccenc.c:29
ff_scc_muxer
AVOutputFormat ff_scc_muxer
Definition: sccenc.c:114
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
AVERROR
#define AVERROR(e)
Definition: error.h:43
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:186
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3880
scc_write_packet
static int scc_write_packet(AVFormatContext *avf, AVPacket *pkt)
Definition: sccenc.c:58
SCCContext::prev_h
int prev_h
Definition: sccenc.c:28
AVFormatContext::nb_streams
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1398
AVFMT_GLOBALHEADER
#define AVFMT_GLOBALHEADER
Format wants global header.
Definition: avformat.h:468
AVOutputFormat::name
const char * name
Definition: avformat.h:507
avcodec_get_name
const char * avcodec_get_name(enum AVCodecID id)
Get the name of a codec.
Definition: utils.c:1127
SCCContext::n
int n
Definition: sccenc.c:30
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
pts
static int64_t pts
Definition: transcode_aac.c:647
SCCContext::prev_s
int prev_s
Definition: sccenc.c:28
avformat.h
Main libavformat public API header.
int
int
Definition: ffmpeg_filter.c:190
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:472
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1370
write_header
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:337
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1020
AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1407
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1423
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
avio_printf
int avio_printf(AVIOContext *s, const char *fmt,...) av_printf_format(2
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