FFmpeg: libavformat/vorbiscomment.c Source File

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libavformat

vorbiscomment.c

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1 /*

2 * VorbisComment writer

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 */

22 #include "avio.h"

23 #include "avformat.h"

24 #include "metadata.h"

25 #include "vorbiscomment.h"

26 #include "libavutil/dict.h"

28 /**

29 * VorbisComment metadata conversion mapping.

30 * from Ogg Vorbis I format specification: comment field and header specification

31 * http://xiph.org/vorbis/doc/v-comment.html

32 */

33 const AVMetadataConv ff_vorbiscomment_metadata_conv[] = {

34 { "ALBUMARTIST", "album_artist"},

35 { "TRACKNUMBER", "track" },

36 { "DISCNUMBER", "disc" },

37 { "DESCRIPTION", "comment" },

38 { 0 }

39 };

41 int64_t ff_vorbiscomment_length(const AVDictionary *m, const char *vendor_string,

42 AVChapter **chapters, unsigned int nb_chapters)

43 {

44 int64_t len = 8;

45 len += strlen(vendor_string);

46 if (chapters && nb_chapters) {

47 for (int i = 0; i < nb_chapters; i++) {

48 AVDictionaryEntry *tag = NULL;

49 len += 4 + 12 + 1 + 10;

50 while ((tag = av_dict_get(chapters[i]->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {

51 int64_t len1 = !strcmp(tag->key, "title") ? 4 : strlen(tag->key);

52 len += 4 + 10 + len1 + 1 + strlen(tag->value);

53 }

54 }

55 }

56 if (m) {

57 AVDictionaryEntry *tag = NULL;

58 while ((tag = av_dict_get(m, "", tag, AV_DICT_IGNORE_SUFFIX))) {

59 len += 4 +strlen(tag->key) + 1 + strlen(tag->value);

60 }

61 }

62 return len;

63 }

65 int ff_vorbiscomment_write(AVIOContext *pb, const AVDictionary *m,

66 const char *vendor_string,

67 AVChapter **chapters, unsigned int nb_chapters)

68 {

69 size_t vendor_string_length = strlen(vendor_string);

70 int cm_count = 0;

71 avio_wl32(pb, vendor_string_length);

72 avio_write(pb, vendor_string, vendor_string_length);

73 if (chapters && nb_chapters) {

74 for (int i = 0; i < nb_chapters; i++) {

75 cm_count += av_dict_count(chapters[i]->metadata) + 1;

76 }

77 }

78 if (m) {

79 int count = av_dict_count(m) + cm_count;

80 AVDictionaryEntry *tag = NULL;

81 avio_wl32(pb, count);

82 while ((tag = av_dict_get(m, "", tag, AV_DICT_IGNORE_SUFFIX))) {

83 int64_t len1 = strlen(tag->key);

84 int64_t len2 = strlen(tag->value);

85 if (len1+1+len2 > UINT32_MAX)

86 return AVERROR(EINVAL);

87 avio_wl32(pb, len1 + 1 + len2);

88 avio_write(pb, tag->key, len1);

89 avio_w8(pb, '=');

90 avio_write(pb, tag->value, len2);

91 }

92 for (int i = 0; i < nb_chapters; i++) {

93 AVChapter *chp = chapters[i];

94 char chapter_time[13];

95 char chapter_number[4];

96 int h, m, s, ms;

98 s = av_rescale(chp->start, chp->time_base.num, chp->time_base.den);

99 h = s / 3600;

100 m = (s / 60) % 60;

101 ms = av_rescale_q(chp->start, chp->time_base, av_make_q( 1, 1000)) % 1000;

102 s = s % 60;

103 snprintf(chapter_number, sizeof(chapter_number), "%03d", i);

104 snprintf(chapter_time, sizeof(chapter_time), "%02d:%02d:%02d.%03d", h, m, s, ms);

105 avio_wl32(pb, 10 + 1 + 12);

106 avio_write(pb, "CHAPTER", 7);

107 avio_write(pb, chapter_number, 3);

108 avio_w8(pb, '=');

109 avio_write(pb, chapter_time, 12);

110

111 tag = NULL;

112 while ((tag = av_dict_get(chapters[i]->metadata, "", tag, AV_DICT_IGNORE_SUFFIX))) {

113 int64_t len1 = !strcmp(tag->key, "title") ? 4 : strlen(tag->key);

114 int64_t len2 = strlen(tag->value);

115 if (len1+1+len2+10 > UINT32_MAX)

116 return AVERROR(EINVAL);

117 avio_wl32(pb, 10 + len1 + 1 + len2);

118 avio_write(pb, "CHAPTER", 7);

119 avio_write(pb, chapter_number, 3);

120 if (!strcmp(tag->key, "title"))

121 avio_write(pb, "NAME", 4);

122 else

123 avio_write(pb, tag->key, len1);

124 avio_w8(pb, '=');

125 avio_write(pb, tag->value, len2);

126 }

127 }

128 } else

129 avio_wl32(pb, 0);

130 return 0;

131 }

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

av_dict_count

int av_dict_count(const AVDictionary *m)

Get number of entries in dictionary.

Definition: dict.c:35

vorbiscomment.h

AVChapter::start

int64_t start

Definition: avformat.h:1175

AV_DICT_IGNORE_SUFFIX

#define AV_DICT_IGNORE_SUFFIX

Return first entry in a dictionary whose first part corresponds to the search key,...

Definition: dict.h:68