[FFmpeg-devel] [PATCH 3/3] lavf/hashenc: clone md5 and framemd5 muxers into hash and framehash muxers

Moritz Barsnick barsnick at gmx.net
Wed Mar 2 15:18:01 CET 2016


The two new muxers are functionally identical, except that they default
to the SHA-512 algorithm instead of MD5. The original "legacy" muxers
continue to provide their MD5 defaults.

The currently supported hash functions are now documented.

Signed-off-by: Moritz Barsnick <barsnick at gmx.net>
---
 Changelog                |   1 +
 doc/muxers.texi          | 129 ++++++++++++++++++++++++++++++++++++-----------
 libavformat/Makefile     |   2 +
 libavformat/allformats.c |   2 +
 libavformat/hashenc.c    |  78 ++++++++++++++++++++++++----
 libavformat/version.h    |   2 +-
 6 files changed, 175 insertions(+), 39 deletions(-)

diff --git a/Changelog b/Changelog
index 0677b33..64a7428 100644
--- a/Changelog
+++ b/Changelog
@@ -9,6 +9,7 @@ version <next>:
 - firequalizer filter
 - datascope filter
 - bench and abench filters
+- hash and framehash filters
 
 
 version 3.0:
diff --git a/doc/muxers.texi b/doc/muxers.texi
index f2ad7fe..c0d1fbf 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -174,25 +174,65 @@ ffmpeg -i INPUT -c:a pcm_u8 -c:v mpeg2video -f framecrc -
 
 See also the @ref{crc} muxer.
 
- at anchor{framemd5}
- at section framemd5
+ at anchor{framehash}
+ at section framehash
 
-Per-packet MD5 testing format.
+Per-packet hash testing format.
 
-This muxer computes and prints the MD5 hash for each audio
-and video packet. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash.
+This muxer computes and prints a cryptographic hash for each audio
+and video packet. This can be used for packet-by-packet equality
+checks without having to individually do a binary comparison on each.
+
+By default audio frames are converted to signed 16-bit raw audio and
+video frames to raw video before computing the hash, but the output
+of explicit conversions to other codecs can also be used. It uses the
+SHA-512 cryptographic hash function by default, but supports several
+further hashes.
 
 The output of the muxer consists of a line for each audio and video
 packet of the form:
 @example
- at var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{MD5}
+ at var{stream_index}, @var{packet_dts}, @var{packet_pts}, @var{packet_duration}, @var{packet_size}, @var{hash}
 @end example
 
- at var{MD5} is a hexadecimal number representing the computed MD5 hash
+ at var{hash} is a hexadecimal number representing the computed hash
 for the packet.
 
+ at table @option
+ at item hash @var{algorithm}
+Use the cryptographic hash function specified by the string @var{algorithm}.
+Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
+ at code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
+ at code{SHA224}, @code{SHA256}, @code{SHA512/224}, @code{SHA512/256},
+ at code{SHA384}, @code{SHA512} (default), @code{CRC32} and @code{adler32}.
+
+ at end table
+
+ at subsection Examples
+
+To compute the SHA-512 hash of the audio and video frames in @file{INPUT},
+converted to raw audio and video packets, and store it in the file
+ at file{out.sha512}:
+ at example
+ffmpeg -i INPUT -f framehash out.sha512
+ at end example
+
+To print the information to stdout, using the MD5 hash function, use
+the command:
+ at example
+ffmpeg -i INPUT -f framehash -hash md5 -
+ at end example
+
+See also the @ref{hash} muxer.
+
+ at anchor{framemd5}
+ at section framemd5
+
+Per-packet MD5 testing format.
+
+This is a variant of the @ref{framehash} muxer. Unlike that muxer,
+it defaults to using the MD5 hash function.
+
 @subsection Examples
 
 For example to compute the MD5 of the audio and video frames in
@@ -202,12 +242,7 @@ in the file @file{out.md5}:
 ffmpeg -i INPUT -f framemd5 out.md5
 @end example
 
-To print the information to stdout, use the command:
- at example
-ffmpeg -i INPUT -f framemd5 -
- at end example
-
-See also the @ref{md5} muxer.
+See also the @ref{framehash} and @ref{md5} muxers.
 
 @anchor{gif}
 @section gif
@@ -243,6 +278,51 @@ ffmpeg -i INPUT -c:v gif -f image2 "out%d.gif"
 Note 2: the GIF format has a very small time base: the delay between two frames
 can not be smaller than one centi second.
 
+ at anchor{hash}
+ at section hash
+
+Hash testing format.
+
+This muxer computes and prints a cryptographic hash of all the input
+audio and video frames. This can be used for equality checks without
+having to do a complete binary comparison.
+
+By default audio frames are converted to signed 16-bit raw audio and
+video frames to raw video before computing the hash, but the output
+of explicit conversions to other codecs can also be used. Timestamps
+are ignored. It uses the SHA-512 cryptographic hash function by default,
+but supports several further hashes.
+
+The output of the muxer consists of a single line of the form:
+ at var{algo}=@var{hash}, where @var{algo} is a short string representing
+the hash function used, and @var{hash} is a hexadecimal number
+representing the computed hash.
+
+ at table @option
+ at item hash @var{algorithm}
+Use the cryptographic hash function specified by the string @var{algorithm}.
+Supported values include @code{MD5}, @code{murmur3}, @code{RIPEMD128},
+ at code{RIPEMD160}, @code{RIPEMD256}, @code{RIPEMD320}, @code{SHA160},
+ at code{SHA224}, @code{SHA256}, @code{SHA512/224}, @code{SHA512/256},
+ at code{SHA384}, @code{SHA512} (default), @code{CRC32} and @code{adler32}.
+
+ at end table
+
+ at subsection Examples
+
+To compute the SHA-512 hash of the input converted to raw audio and
+video, and store it in the file @file{out.sha512}:
+ at example
+ffmpeg -i INPUT -f hash out.sha512
+ at end example
+
+To print an MD5 hash to stdout use the command:
+ at example
+ffmpeg -i INPUT -f hash -hash md5 -
+ at end example
+
+See also the @ref{framehash} muxer.
+
 @anchor{hls}
 @section hls
 
@@ -621,27 +701,18 @@ have no effect if it is not.
 
 MD5 testing format.
 
-This muxer computes and prints the MD5 hash of all the input audio
-and video frames. By default audio frames are converted to signed
-16-bit raw audio and video frames to raw video before computing the
-hash. Timestamps are ignored.
+This is a variant of the @ref{hash} muxer. Unlike that muxer, it
+defaults to using the MD5 hash function.
 
-The output of the muxer consists of a single line of the form:
-MD5=@var{MD5}, where @var{MD5} is a hexadecimal number representing
-the computed MD5 hash.
+ at subsection Examples
 
-For example to compute the MD5 hash of the input converted to raw
+To compute the MD5 hash of the input converted to raw
 audio and video, and store it in the file @file{out.md5}:
 @example
 ffmpeg -i INPUT -f md5 out.md5
 @end example
 
-You can print the MD5 to stdout with the command:
- at example
-ffmpeg -i INPUT -f md5 -
- at end example
-
-See also the @ref{framemd5} muxer.
+See also the @ref{hash} and @ref{framemd5} muxers.
 
 @section mov, mp4, ismv
 
diff --git a/libavformat/Makefile b/libavformat/Makefile
index 05c0fe8..72c810a 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -173,6 +173,7 @@ OBJS-$(CONFIG_LIVE_FLV_DEMUXER)          += flvdec.o
 OBJS-$(CONFIG_FLV_MUXER)                 += flvenc.o avc.o
 OBJS-$(CONFIG_FOURXM_DEMUXER)            += 4xm.o
 OBJS-$(CONFIG_FRAMECRC_MUXER)            += framecrcenc.o framehash.o
+OBJS-$(CONFIG_FRAMEHASH_MUXER)           += hashenc.o framehash.o
 OBJS-$(CONFIG_FRAMEMD5_MUXER)            += hashenc.o framehash.o
 OBJS-$(CONFIG_FRM_DEMUXER)               += frmdec.o
 OBJS-$(CONFIG_FSB_DEMUXER)               += fsb.o
@@ -193,6 +194,7 @@ OBJS-$(CONFIG_H263_DEMUXER)              += h263dec.o rawdec.o
 OBJS-$(CONFIG_H263_MUXER)                += rawenc.o
 OBJS-$(CONFIG_H264_DEMUXER)              += h264dec.o rawdec.o
 OBJS-$(CONFIG_H264_MUXER)                += rawenc.o
+OBJS-$(CONFIG_HASH_MUXER)                += hashenc.o
 OBJS-$(CONFIG_HDS_MUXER)                 += hdsenc.o
 OBJS-$(CONFIG_HEVC_DEMUXER)              += hevcdec.o rawdec.o
 OBJS-$(CONFIG_HEVC_MUXER)                += rawenc.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index 94f258d..792fe85 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -130,6 +130,7 @@ void av_register_all(void)
     REGISTER_DEMUXER (LIVE_FLV,         live_flv);
     REGISTER_DEMUXER (FOURXM,           fourxm);
     REGISTER_MUXER   (FRAMECRC,         framecrc);
+    REGISTER_MUXER   (FRAMEHASH,        framehash);
     REGISTER_MUXER   (FRAMEMD5,         framemd5);
     REGISTER_DEMUXER (FRM,              frm);
     REGISTER_DEMUXER (FSB,              fsb);
@@ -143,6 +144,7 @@ void av_register_all(void)
     REGISTER_MUXDEMUX(H261,             h261);
     REGISTER_MUXDEMUX(H263,             h263);
     REGISTER_MUXDEMUX(H264,             h264);
+    REGISTER_MUXER   (HASH,             hash);
     REGISTER_MUXER   (HDS,              hds);
     REGISTER_MUXDEMUX(HEVC,             hevc);
     REGISTER_MUXDEMUX(HLS,              hls);
diff --git a/libavformat/hashenc.c b/libavformat/hashenc.c
index e4d308d..50c816a 100644
--- a/libavformat/hashenc.c
+++ b/libavformat/hashenc.c
@@ -54,20 +54,23 @@ static void hash_finish(struct AVFormatContext *s, char *buf)
 
 #define OFFSET(x) offsetof(struct HashContext, x)
 #define ENC AV_OPT_FLAG_ENCODING_PARAM
-static const AVOption md5_options[] = {
-    { "hash", "set hash to use", OFFSET(hash_name), AV_OPT_TYPE_STRING, {.str = "md5"}, 0, 0, ENC },
+#if CONFIG_HASH_MUXER || CONFIG_FRAMEHASH_MUXER
+static const AVOption hash_options[] = {
+    { "hash", "set hash to use", OFFSET(hash_name), AV_OPT_TYPE_STRING, {.str = "sha512"}, 0, 0, ENC },
     { "format_version", "file format version", OFFSET(format_version), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 1, ENC },
     { NULL },
 };
+#endif
 
-static const AVClass md5enc_class = {
-    .class_name = "hash encoder class",
-    .item_name  = av_default_item_name,
-    .option     = md5_options,
-    .version    = LIBAVUTIL_VERSION_INT,
+#if CONFIG_MD5_MUXER || CONFIG_FRAMEMD5_MUXER
+static const AVOption md5_options[] = {
+    { "hash", "set hash to use", OFFSET(hash_name), AV_OPT_TYPE_STRING, {.str = "md5"}, 0, 0, ENC },
+    { "format_version", "file format version", OFFSET(format_version), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 1, ENC },
+    { NULL },
 };
+#endif
 
-#if CONFIG_MD5_MUXER
+#if CONFIG_HASH_MUXER || CONFIG_MD5_MUXER
 static int hash_write_header(struct AVFormatContext *s)
 {
     struct HashContext *c = s->priv_data;
@@ -97,6 +100,38 @@ static int hash_write_trailer(struct AVFormatContext *s)
     av_hash_freep(&c->hash);
     return 0;
 }
+#endif
+
+#if CONFIG_HASH_MUXER
+static const AVClass hashenc_class = {
+    .class_name = "hash encoder class",
+    .item_name  = av_default_item_name,
+    .option     = hash_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_hash_muxer = {
+    .name              = "hash",
+    .long_name         = NULL_IF_CONFIG_SMALL("Hash testing"),
+    .priv_data_size    = sizeof(struct HashContext),
+    .audio_codec       = AV_CODEC_ID_PCM_S16LE,
+    .video_codec       = AV_CODEC_ID_RAWVIDEO,
+    .write_header      = hash_write_header,
+    .write_packet      = hash_write_packet,
+    .write_trailer     = hash_write_trailer,
+    .flags             = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT |
+                         AVFMT_TS_NEGATIVE,
+    .priv_class        = &hashenc_class,
+};
+#endif
+
+#if CONFIG_MD5_MUXER
+static const AVClass md5enc_class = {
+    .class_name = "MD5 encoder class",
+    .item_name  = av_default_item_name,
+    .option     = md5_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
 
 AVOutputFormat ff_md5_muxer = {
     .name              = "md5",
@@ -113,7 +148,7 @@ AVOutputFormat ff_md5_muxer = {
 };
 #endif
 
-#if CONFIG_FRAMEMD5_MUXER
+#if CONFIG_FRAMEHASH_MUXER || CONFIG_FRAMEMD5_MUXER
 static int framehash_write_header(struct AVFormatContext *s)
 {
     struct HashContext *c = s->priv_data;
@@ -147,7 +182,32 @@ static int framehash_write_trailer(struct AVFormatContext *s)
     av_hash_freep(&c->hash);
     return 0;
 }
+#endif
+
+#if CONFIG_FRAMEHASH_MUXER
+static const AVClass framehash_class = {
+    .class_name = "frame hash encoder class",
+    .item_name  = av_default_item_name,
+    .option     = hash_options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_framehash_muxer = {
+    .name              = "framehash",
+    .long_name         = NULL_IF_CONFIG_SMALL("Per-frame hash testing"),
+    .priv_data_size    = sizeof(struct HashContext),
+    .audio_codec       = AV_CODEC_ID_PCM_S16LE,
+    .video_codec       = AV_CODEC_ID_RAWVIDEO,
+    .write_header      = framehash_write_header,
+    .write_packet      = framehash_write_packet,
+    .write_trailer     = framehash_write_trailer,
+    .flags             = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT |
+                         AVFMT_TS_NEGATIVE,
+    .priv_class        = &framehash_class,
+};
+#endif
 
+#if CONFIG_FRAMEMD5_MUXER
 static const AVClass framemd5_class = {
     .class_name = "frame hash encoder class",
     .item_name  = av_default_item_name,
diff --git a/libavformat/version.h b/libavformat/version.h
index 29aca66..7dcce2c 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,7 +30,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVFORMAT_VERSION_MAJOR  57
-#define LIBAVFORMAT_VERSION_MINOR  27
+#define LIBAVFORMAT_VERSION_MINOR  28
 #define LIBAVFORMAT_VERSION_MICRO 100
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
-- 
2.5.0



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