FFmpeg: libavformat/omaenc.c Source File

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libavformat

omaenc.c

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1 /*

2 * Sony OpenMG (OMA) muxer

3 *

5 *

6 * This file is part of FFmpeg.

7 *

8 * FFmpeg is free software; you can redistribute it and/or

9 * modify it under the terms of the GNU Lesser General Public

10 * License as published by the Free Software Foundation; either

11 * version 2.1 of the License, or (at your option) any later version.

12 *

13 * FFmpeg is distributed in the hope that it will be useful,

14 * but WITHOUT ANY WARRANTY; without even the implied warranty of

15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

16 * Lesser General Public License for more details.

17 *

18 * You should have received a copy of the GNU Lesser General Public

19 * License along with FFmpeg; if not, write to the Free Software

20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

21 */

23 #include "avformat.h"

24 #include "avio_internal.h"

25 #include "id3v2.h"

26 #include "internal.h"

27 #include "oma.h"

28 #include "rawenc.h"

30 static av_cold int oma_write_header(AVFormatContext *s)

31 {

32 AVCodecParameters *par;

33 int srate_index;

34 int isjointstereo;

36 par = s->streams[0]->codecpar;

37 /* check for support of the format first */

39 for (srate_index = 0; ; srate_index++) {

40 if (ff_oma_srate_tab[srate_index] == 0) {

41 av_log(s, AV_LOG_ERROR, "Sample rate %d not supported in OpenMG audio\n",

42 par->sample_rate);

43 return AVERROR(EINVAL);

44 }

46 if (ff_oma_srate_tab[srate_index] * 100 == par->sample_rate)

47 break;

48 }

50 /* Metadata; OpenMG does not support ID3v2.4 */

51 ff_id3v2_write_simple(s, 3, ID3v2_EA3_MAGIC);

53 ffio_wfourcc(s->pb, "EA30円");

54 avio_w8(s->pb, EA3_HEADER_SIZE >> 7);

55 avio_w8(s->pb, EA3_HEADER_SIZE & 0x7F);

56 avio_wl16(s->pb, 0xFFFF); /* not encrypted */

57 ffio_fill(s->pb, 0, 6 * 4); /* Padding + DRM id */

59 switch (par->codec_tag) {

60 case OMA_CODECID_ATRAC3:

61 if (par->ch_layout.nb_channels != 2) {

62 av_log(s, AV_LOG_ERROR, "ATRAC3 in OMA is only supported with 2 channels\n");

63 return AVERROR(EINVAL);

64 }

65 if (par->extradata_size == 14) /* WAV format extradata */

66 isjointstereo = par->extradata[6] != 0;

67 else if(par->extradata_size == 10) /* RM format extradata */

68 isjointstereo = par->extradata[8] == 0x12;

69 else {

70 av_log(s, AV_LOG_ERROR, "ATRAC3: Unsupported extradata size\n");

71 return AVERROR(EINVAL);

72 }

73 avio_wb32(s->pb, (OMA_CODECID_ATRAC3 << 24) |

74 (isjointstereo << 17) |

75 (srate_index << 13) |

76 (par->block_align/8));

77 break;

78 case OMA_CODECID_ATRAC3P:

79 avio_wb32(s->pb, (OMA_CODECID_ATRAC3P << 24) |

80 (srate_index << 13) |

81 (par->ch_layout.nb_channels << 10) |

82 (par->block_align/8 - 1));

83 break;

84 default:

85 av_log(s, AV_LOG_ERROR, "unsupported codec tag %s for write\n",

86 av_fourcc2str(par->codec_tag));

87 return AVERROR(EINVAL);

88 }

89 ffio_fill(s->pb, 0, EA3_HEADER_SIZE - 36); /* Padding */

91 return 0;

92 }

94 const AVOutputFormat ff_oma_muxer = {

95 .name = "oma",

96 .long_name = NULL_IF_CONFIG_SMALL("Sony OpenMG audio"),

97 .mime_type = "audio/x-oma",

98 .extensions = "oma",

99 .audio_codec = AV_CODEC_ID_ATRAC3,

100 .write_header = oma_write_header,

101 .write_packet = ff_raw_write_packet,

102 .codec_tag = ff_oma_codec_tags_list,

103 .flags = AVFMT_NOTIMESTAMPS,

104 };

oma.h

AVCodecParameters::extradata

uint8_t * extradata

Extra binary data needed for initializing the decoder, codec-dependent.

Definition: codec_par.h:75

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

ffio_wfourcc

static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)

Definition: avio_internal.h:116

AVCodecParameters

This struct describes the properties of an encoded stream.

Definition: codec_par.h:53

ff_oma_codec_tags_list

const AVCodecTag *const ff_oma_codec_tags_list[]

Definition: oma.c:38

AVFMT_NOTIMESTAMPS

#define AVFMT_NOTIMESTAMPS

Format does not need / have any timestamps.