[FFmpeg-cvslog] avformat/cafdec: Implement FLAC-in-CAF parsing
Martijn van Beurden
git at videolan.org
Tue Jul 5 15:13:17 EEST 2022
ffmpeg | branch: master | Martijn van Beurden <mvanb1 at gmail.com> | Sat Jun 11 09:31:12 2022 +0200| [056a9fac5b8fef3b9f5abeb5bf581a3e52e28a37] | committer: Paul B Mahol
avformat/cafdec: Implement FLAC-in-CAF parsing
The afconvert utility shipped with MacOS supports muxing of FLAC
in CAF, see afconvert help output on a recent Mac here:
https://hydrogenaud.io/index.php?topic=122509.0 A file created
with afconvert free of copyright (licensed CC0) can be found here:
http://www.audiograaf.nl/misc_stuff/afconvert-FLAC-in-CAF.caf
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=056a9fac5b8fef3b9f5abeb5bf581a3e52e28a37
---
libavformat/caf.c | 1 +
libavformat/cafdec.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 45 insertions(+)
diff --git a/libavformat/caf.c b/libavformat/caf.c
index a700e4055b..a61c39fae5 100644
--- a/libavformat/caf.c
+++ b/libavformat/caf.c
@@ -46,6 +46,7 @@ const AVCodecTag ff_codec_caf_tags[] = {
{ AV_CODEC_ID_GSM, MKTAG('a','g','s','m') },
{ AV_CODEC_ID_GSM_MS, MKTAG('m','s', 0, '1') },
{ AV_CODEC_ID_ILBC, MKTAG('i','l','b','c') },
+ { AV_CODEC_ID_FLAC, MKTAG('f','l','a','c') },
{ AV_CODEC_ID_MACE3, MKTAG('M','A','C','3') },
{ AV_CODEC_ID_MACE6, MKTAG('M','A','C','6') },
{ AV_CODEC_ID_MP1, MKTAG('.','m','p','1') },
diff --git a/libavformat/cafdec.c b/libavformat/cafdec.c
index 168f69f20b..d5b8c38c25 100644
--- a/libavformat/cafdec.c
+++ b/libavformat/cafdec.c
@@ -32,6 +32,7 @@
#include "internal.h"
#include "isom.h"
#include "mov_chan.h"
+#include "libavcodec/flac.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/intfloat.h"
#include "libavutil/dict.h"
@@ -170,6 +171,49 @@ static int read_kuki_chunk(AVFormatContext *s, int64_t size)
}
avio_skip(pb, size - ALAC_NEW_KUKI);
}
+ } else if (st->codecpar->codec_id == AV_CODEC_ID_FLAC) {
+ int last, type, flac_metadata_size;
+ uint8_t buf[4];
+ /* The magic cookie format for FLAC consists mostly of an mp4 dfLa atom. */
+ if (size < (16 + FLAC_STREAMINFO_SIZE)) {
+ av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
+ return AVERROR_INVALIDDATA;
+ }
+ /* Check cookie version. */
+ if (avio_r8(pb) != 0) {
+ av_log(s, AV_LOG_ERROR, "unknown FLAC magic cookie\n");
+ return AVERROR_INVALIDDATA;
+ }
+ avio_rb24(pb); /* Flags */
+ /* read dfLa fourcc */
+ if (avio_read(pb, buf, 4) != 4) {
+ av_log(s, AV_LOG_ERROR, "failed to read FLAC magic cookie\n");
+ return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
+ }
+ if (memcmp(buf, "dfLa", 4)) {
+ av_log(s, AV_LOG_ERROR, "invalid FLAC magic cookie\n");
+ return AVERROR_INVALIDDATA;
+ }
+ /* Check dfLa version. */
+ if (avio_r8(pb) != 0) {
+ av_log(s, AV_LOG_ERROR, "unknown dfLa version\n");
+ return AVERROR_INVALIDDATA;
+ }
+ avio_rb24(pb); /* Flags */
+ if (avio_read(pb, buf, sizeof(buf)) != sizeof(buf)) {
+ av_log(s, AV_LOG_ERROR, "failed to read FLAC metadata block header\n");
+ return pb->error < 0 ? pb->error : AVERROR_INVALIDDATA;
+ }
+ flac_parse_block_header(buf, &last, &type, &flac_metadata_size);
+ if (type != FLAC_METADATA_TYPE_STREAMINFO || flac_metadata_size != FLAC_STREAMINFO_SIZE) {
+ av_log(s, AV_LOG_ERROR, "STREAMINFO must be first FLACMetadataBlock\n");
+ return AVERROR_INVALIDDATA;
+ }
+ ret = ff_get_extradata(s, st->codecpar, pb, FLAC_STREAMINFO_SIZE);
+ if (ret < 0)
+ return ret;
+ if (!last)
+ av_log(s, AV_LOG_WARNING, "non-STREAMINFO FLACMetadataBlock(s) ignored\n");
} else if (st->codecpar->codec_id == AV_CODEC_ID_OPUS) {
// The data layout for Opus is currently unknown, so we do not export
// extradata at all. Multichannel streams are not supported.
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