[FFmpeg-devel] [PATCH] lavf/matroska: expose stream encoding as global side-data
Rodger Combs
rodger.combs at gmail.com
Tue Sep 13 05:45:14 EEST 2016
Some demuxers can't handle Matroska compression, so this lets API users
check if a file uses it and determine whether those players will fail.
Currently only exports the first encoding; the format technically supports
multiple, but I can't find an example of this and lavf doesn't support it.
---
doc/APIchanges | 4 ++++
libavcodec/avcodec.h | 43 ++++++++++++++++++++++++++++++++++++++++++-
libavcodec/avpacket.c | 1 +
libavcodec/version.h | 4 ++--
libavformat/matroskadec.c | 23 +++++++++++++++++------
5 files changed, 66 insertions(+), 9 deletions(-)
diff --git a/doc/APIchanges b/doc/APIchanges
index 7ac809c..144bfac 100644
--- a/doc/APIchanges
+++ b/doc/APIchanges
@@ -15,6 +15,10 @@ libavutil: 2015-08-28
API changes, most recent first:
+2016-09-12 - xxxxxxx - lavc 57.56.100 - avcodec.h
+ Add AVMatroskaEncoding and its constituent enums
+ (AVMatroskaEncodingType and AVMatroskaEncodingAlgorithm)
+
2016-08-29 - 4493390 - lavfi 6.58.100 - avfilter.h
Add AVFilterContext.nb_threads.
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 01f9b29..4cca01f 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1330,6 +1330,42 @@ typedef struct AVCPBProperties {
uint64_t vbv_delay;
} AVCPBProperties;
+/**
+ * Basic type of encoding in a Matroska stream
+ */
+typedef enum AVMatroskaEncodingType {
+ AV_MATROSKA_ENCODING_COMPRESSION = 0,
+ AV_MATROSKA_ENCODING_ENCRYPTION = 1,
+} AVMatroskaEncodingType;
+
+/**
+ * Encoding algorithm in a Matroska stream
+ */
+typedef enum AVMatroskaEncodingAlgorithm {
+ // Compression
+ AV_MATROSKA_ENCODING_ZLIB = 0,
+ AV_MATROSKA_ENCODING_BZLIB = 1,
+ AV_MATROSKA_ENCODING_LZO1X = 2,
+ AV_MATROSKA_ENCODING_HEADERSTRIPPING = 3,
+ // Encryption
+ AV_MATROSKA_ENCODING_SIGNING = 0,
+ AV_MATROSKA_ENCODING_DES = 1,
+ AV_MATROSKA_ENCODING_3DES = 2,
+ AV_MATROSKA_ENCODING_TWOFISH = 3,
+ AV_MATROSKA_ENCODING_BLOWFISH = 4,
+ AV_MATROSKA_ENCODING_AES = 5,
+} AVMatroskaEncodingAlgorithm;
+
+/**
+ * This structure describes the Matroska encoding (compression or encryption) applied to
+ * a stream. It can be useful when determining whether or not other demuxers can handle
+ * a file, since some players don't support header compression.
+ */
+typedef struct AVMatroskaEncoding {
+ AVMatroskaEncodingType type;
+ AVMatroskaEncodingAlgorithm algorithm;
+} AVMatroskaEncoding;
+
#if FF_API_QSCALE_TYPE
#define FF_QSCALE_TYPE_MPEG1 0
#define FF_QSCALE_TYPE_MPEG2 1
@@ -1525,7 +1561,12 @@ enum AVPacketSideDataType {
* should be associated with a video stream and containts data in the form
* of the AVMasteringDisplayMetadata struct.
*/
- AV_PKT_DATA_MASTERING_DISPLAY_METADATA
+ AV_PKT_DATA_MASTERING_DISPLAY_METADATA,
+
+ /**
+ * Corresponds to the AVMatroskaEncoding struct.
+ */
+ AV_PKT_DATA_MATROSKA_ENCODING,
};
#define AV_PKT_DATA_QUALITY_FACTOR AV_PKT_DATA_QUALITY_STATS //DEPRECATED
diff --git a/libavcodec/avpacket.c b/libavcodec/avpacket.c
index fa2844d..220e305 100644
--- a/libavcodec/avpacket.c
+++ b/libavcodec/avpacket.c
@@ -367,6 +367,7 @@ const char *av_packet_side_data_name(enum AVPacketSideDataType type)
case AV_PKT_DATA_METADATA_UPDATE: return "Metadata Update";
case AV_PKT_DATA_MPEGTS_STREAM_ID: return "MPEGTS Stream ID";
case AV_PKT_DATA_MASTERING_DISPLAY_METADATA: return "Mastering display metadata";
+ case AV_PKT_DATA_MATROSKA_ENCODING: return "Matroska Encoding";
}
return NULL;
}
diff --git a/libavcodec/version.h b/libavcodec/version.h
index f5dd118..ecd48c5 100644
--- a/libavcodec/version.h
+++ b/libavcodec/version.h
@@ -28,8 +28,8 @@
#include "libavutil/version.h"
#define LIBAVCODEC_VERSION_MAJOR 57
-#define LIBAVCODEC_VERSION_MINOR 55
-#define LIBAVCODEC_VERSION_MICRO 101
+#define LIBAVCODEC_VERSION_MINOR 56
+#define LIBAVCODEC_VERSION_MICRO 100
#define LIBAVCODEC_VERSION_INT AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
LIBAVCODEC_VERSION_MINOR, \
diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 77b8a5d..9bae9c8 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -1919,6 +1919,10 @@ static int matroska_parse_tracks(AVFormatContext *s)
if (!track->codec_id)
continue;
+ st = track->stream = avformat_new_stream(s, NULL);
+ if (!st)
+ return AVERROR(ENOMEM);
+
if (track->audio.samplerate < 0 || track->audio.samplerate > INT_MAX ||
isnan(track->audio.samplerate)) {
av_log(matroska->ctx, AV_LOG_WARNING,
@@ -1944,7 +1948,16 @@ static int matroska_parse_tracks(AVFormatContext *s)
av_log(matroska->ctx, AV_LOG_ERROR,
"Multiple combined encodings not supported");
} else if (encodings_list->nb_elem == 1) {
+ AVMatroskaEncoding *side_data = (void*)av_stream_new_side_data(st,
+ AV_PKT_DATA_MATROSKA_ENCODING,
+ sizeof(AVMatroskaEncoding));
+ if (!side_data)
+ return AVERROR(ENOMEM);
+
+ side_data->type = encodings[0].type;
+
if (encodings[0].type) {
+ side_data->algorithm = encodings[0].encryption.algo;
if (encodings[0].encryption.key_id.size > 0) {
/* Save the encryption key id to be stored later as a
metadata tag. */
@@ -1972,10 +1985,12 @@ static int matroska_parse_tracks(AVFormatContext *s)
encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_LZO &&
#endif
encodings[0].compression.algo != MATROSKA_TRACK_ENCODING_COMP_HEADERSTRIP) {
+ side_data->algorithm = encodings[0].compression.algo;
encodings[0].scope = 0;
av_log(matroska->ctx, AV_LOG_ERROR,
"Unsupported encoding type");
} else if (track->codec_priv.size && encodings[0].scope & 2) {
+ side_data->algorithm = encodings[0].compression.algo;
uint8_t *codec_priv = track->codec_priv.data;
int ret = matroska_decode_buffer(&track->codec_priv.data,
&track->codec_priv.size,
@@ -1989,6 +2004,8 @@ static int matroska_parse_tracks(AVFormatContext *s)
if (codec_priv != track->codec_priv.data)
av_free(codec_priv);
+ } else {
+ side_data->algorithm = encodings[0].compression.algo;
}
}
@@ -2000,12 +2017,6 @@ static int matroska_parse_tracks(AVFormatContext *s)
}
}
- st = track->stream = avformat_new_stream(s, NULL);
- if (!st) {
- av_free(key_id_base64);
- return AVERROR(ENOMEM);
- }
-
if (key_id_base64) {
/* export encryption key id as base64 metadata tag */
av_dict_set(&st->metadata, "enc_key_id", key_id_base64, 0);
--
2.10.0
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