FFmpeg: libavcodec/assenc.c Source File

FFmpeg

libavcodec

assenc.c

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1 /*

2 * SSA/ASS encoder

3 * Copyright (c) 2010 Aurelien Jacobs <aurel@gnuage.org>

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 "config_components.h"

23

24 #include <string.h>

25

26 #include "avcodec.h"

27 #include "ass.h"

28 #include "codec_internal.h"

29 #include "libavutil/avstring.h"

30 #include "libavutil/internal.h"

31 #include "libavutil/mem.h"

32

33 static av_cold int ass_encode_init(AVCodecContext *avctx)

34 {

35 avctx->extradata = av_malloc(avctx->subtitle_header_size + 1);

36 if (!avctx->extradata)

37 return AVERROR(ENOMEM);

38 memcpy(avctx->extradata, avctx->subtitle_header, avctx->subtitle_header_size);

39 avctx->extradata_size = avctx->subtitle_header_size;

40 avctx->extradata[avctx->extradata_size] = 0;

41 return 0;

42 }

43

44 static int ass_encode_frame(AVCodecContext *avctx,

45 unsigned char *buf, int bufsize,

46 const AVSubtitle *sub)

47 {

48 size_t len;

49

50 if (sub->num_rects != 1) {

51 av_log(avctx, AV_LOG_ERROR, "Only one rect per AVSubtitle is supported in ASS.\n");

52 return AVERROR_INVALIDDATA;

53 }

54

55 if (sub->rects[0]->type != SUBTITLE_ASS) {

56 av_log(avctx, AV_LOG_ERROR, "Only SUBTITLE_ASS type supported.\n");

57 return AVERROR(EINVAL);

58 }

59

60 len = av_strlcpy(buf, sub->rects[0]->ass, bufsize);

61

62 if (len >= bufsize) {

63 av_log(avctx, AV_LOG_ERROR, "Buffer too small for ASS event.\n");

64 return AVERROR_BUFFER_TOO_SMALL;

65 }

66

67 return len;

68 }

69

70 #if CONFIG_SSA_ENCODER

71 const FFCodec ff_ssa_encoder = {

72 .p.name = "ssa",

73 CODEC_LONG_NAME("ASS (Advanced SubStation Alpha) subtitle"),

74 .p.type = AVMEDIA_TYPE_SUBTITLE,

75 .p.id = AV_CODEC_ID_ASS,

76 .init = ass_encode_init,

77 FF_CODEC_ENCODE_SUB_CB(ass_encode_frame),

78 };

79 #endif

80

81 #if CONFIG_ASS_ENCODER

82 const FFCodec ff_ass_encoder = {

83 .p.name = "ass",

84 CODEC_LONG_NAME("ASS (Advanced SubStation Alpha) subtitle"),

85 .p.type = AVMEDIA_TYPE_SUBTITLE,

86 .p.id = AV_CODEC_ID_ASS,

87 .init = ass_encode_init,

88 FF_CODEC_ENCODE_SUB_CB(ass_encode_frame),

89 };

90 #endif

Definition: avcodec.h:2238

AVMEDIA_TYPE_SUBTITLE

@ AVMEDIA_TYPE_SUBTITLE

Definition: avutil.h:204

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

AVSubtitle::rects

AVSubtitleRect ** rects

Definition: avcodec.h:2243

AVSubtitle::num_rects

unsigned num_rects

Definition: avcodec.h:2242

Definition: codec_internal.h:127

AVCodecContext::subtitle_header

uint8_t * subtitle_header

Definition: avcodec.h:1902

#define av_malloc(s)

Definition: tableprint_vlc.h:30

@ SUBTITLE_ASS

Formatted text, the ass field must be set by the decoder and is authoritative.

Definition: avcodec.h:2206

AV_CODEC_ID_ASS

@ AV_CODEC_ID_ASS

Definition: codec_id.h:572

AVCodec p

The public AVCodec.

Definition: codec_internal.h:131

AVERROR_BUFFER_TOO_SMALL

#define AVERROR_BUFFER_TOO_SMALL

Buffer too small.

Definition: error.h:53

AVSubtitleRect::ass

char * ass

0 terminated ASS/SSA compatible event line.

Definition: avcodec.h:2235

const FFCodec ff_ass_encoder

#define AV_LOG_ERROR

Something went wrong and cannot losslessly be recovered.

Definition: log.h:180

#define av_cold

Definition: attributes.h:90

AVCodecContext::extradata_size

int extradata_size

Definition: avcodec.h:530

const FFCodec ff_ssa_encoder

CODEC_LONG_NAME

#define CODEC_LONG_NAME(str)

Definition: codec_internal.h:296

AVCodecContext::subtitle_header_size

int subtitle_header_size

Header containing style information for text subtitles.

Definition: avcodec.h:1901

FF_CODEC_ENCODE_SUB_CB

#define FF_CODEC_ENCODE_SUB_CB(func)

Definition: codec_internal.h:323

codec_internal.h

AVSubtitleRect::type

enum AVSubtitleType type

Definition: avcodec.h:2226

ass_encode_frame

static int ass_encode_frame(AVCodecContext *avctx, unsigned char *buf, int bufsize, const AVSubtitle *sub)

Definition: assenc.c:44

AVCodecContext::extradata

uint8_t * extradata

some codecs need / can use extradata like Huffman tables.

Definition: avcodec.h:529

const char * name

Name of the codec implementation.

Definition: codec.h:194

int len

Definition: vorbis_enc_data.h:426

main external API structure.

Definition: avcodec.h:451

ass_encode_init

static av_cold int ass_encode_init(AVCodecContext *avctx)

Definition: assenc.c:33

size_t av_strlcpy(char *dst, const char *src, size_t size)

Copy the string src to dst, but no more than size - 1 bytes, and null-terminate dst.

Definition: avstring.c:85

#define av_log(a,...)

Definition: tableprint_vlc.h:27

AVERROR_INVALIDDATA

#define AVERROR_INVALIDDATA

Invalid data found when processing input.

Definition: error.h:61

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