[FFmpeg-devel] [PATCH v2 3/3] avformat/hashenc: add streamhash muxer
Moritz Barsnick
barsnick at gmx.net
Wed Sep 11 16:34:32 EEST 2019
Implemented as a variant of the hash muxer, reusing most functions,
and making use of the previously introduced array of hashes.
---
Changelog | 1 +
doc/muxers.texi | 46 ++++++++++++++++++++++
libavformat/Makefile | 1 +
libavformat/allformats.c | 1 +
libavformat/hashenc.c | 82 +++++++++++++++++++++++++++++++++++-----
libavformat/version.h | 4 +-
6 files changed, 124 insertions(+), 11 deletions(-)
diff --git a/Changelog b/Changelog
index 4b29e015a0..8eeed65680 100644
--- a/Changelog
+++ b/Changelog
@@ -9,6 +9,7 @@ version <next>:
- Supoort AMD AMF encoder on Linux (via Vulkan)
- IMM5 video decoder
- ZeroMQ protocol
+- streamhash muxer
version 4.2:
diff --git a/doc/muxers.texi b/doc/muxers.texi
index 20d31b279c..014f952d68 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -2064,6 +2064,52 @@ Specify whether to remove all fragments when finished. Default 0 (do not remove)
@end table
+ at anchor{streamhash}
+ at section streamhash
+
+Per stream hash testing format.
+
+This muxer computes and prints a cryptographic hash of all the input frames,
+on a per-stream basis. 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-256 cryptographic hash function by default,
+but supports several other algorithms.
+
+The output of the muxer consists of one line per stream of the form:
+ at var{streamindex}, at var{algo}=@var{hash}, where @var{streamindex} is the
+index of the mapped stream, @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} (default), @code{SHA512/224}, @code{SHA512/256},
+ at code{SHA384}, @code{SHA512}, @code{CRC32} and @code{adler32}.
+
+ at end table
+
+ at subsection Examples
+
+To compute the SHA-256 hash of the input converted to raw audio and
+video, and store it in the file @file{out.sha256}:
+ at example
+ffmpeg -i INPUT -f streamhash out.sha256
+ at end example
+
+To print an MD5 hash to stdout use the command:
+ at example
+ffmpeg -i INPUT -f streamhash -hash md5 -
+ at end example
+
+See also the @ref{hash} and @ref{framehash} muxers.
+
@anchor{fifo}
@section fifo
diff --git a/libavformat/Makefile b/libavformat/Makefile
index efa3a112ae..a61d42b721 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -494,6 +494,7 @@ OBJS-$(CONFIG_SRT_DEMUXER) += srtdec.o subtitles.o
OBJS-$(CONFIG_SRT_MUXER) += srtenc.o
OBJS-$(CONFIG_STL_DEMUXER) += stldec.o subtitles.o
OBJS-$(CONFIG_STR_DEMUXER) += psxstr.o
+OBJS-$(CONFIG_STREAMHASH_MUXER) += hashenc.o
OBJS-$(CONFIG_STREAM_SEGMENT_MUXER) += segment.o
OBJS-$(CONFIG_SUBVIEWER1_DEMUXER) += subviewer1dec.o subtitles.o
OBJS-$(CONFIG_SUBVIEWER_DEMUXER) += subviewerdec.o subtitles.o
diff --git a/libavformat/allformats.c b/libavformat/allformats.c
index cd00834807..f7fea32b45 100644
--- a/libavformat/allformats.c
+++ b/libavformat/allformats.c
@@ -393,6 +393,7 @@ extern AVInputFormat ff_srt_demuxer;
extern AVOutputFormat ff_srt_muxer;
extern AVInputFormat ff_str_demuxer;
extern AVInputFormat ff_stl_demuxer;
+extern AVOutputFormat ff_streamhash_muxer;
extern AVInputFormat ff_subviewer1_demuxer;
extern AVInputFormat ff_subviewer_demuxer;
extern AVInputFormat ff_sup_demuxer;
diff --git a/libavformat/hashenc.c b/libavformat/hashenc.c
index 4fd41e41b6..18dc4dc825 100644
--- a/libavformat/hashenc.c
+++ b/libavformat/hashenc.c
@@ -31,6 +31,7 @@ struct HashContext {
const AVClass *avclass;
struct AVHashContext **hashes;
char *hash_name;
+ int per_stream;
int format_version;
};
@@ -56,6 +57,13 @@ static const AVOption framehash_options[] = {
};
#endif
+#if CONFIG_STREAMHASH_MUXER
+static const AVOption streamhash_options[] = {
+ HASH_OPT("sha256"),
+ { NULL },
+};
+#endif
+
#if CONFIG_MD5_MUXER
static const AVOption md5_options[] = {
HASH_OPT("md5"),
@@ -76,6 +84,7 @@ static int hash_init(struct AVFormatContext *s)
{
int res;
struct HashContext *c = s->priv_data;
+ c->per_stream = 0;
c->hashes = av_mallocz_array(1, sizeof(c->hashes));
if (!c->hashes)
return AVERROR(ENOMEM);
@@ -87,24 +96,32 @@ static int hash_init(struct AVFormatContext *s)
av_hash_init(c->hashes[0]);
return 0;
}
+#endif
+#if CONFIG_HASH_MUXER || CONFIG_MD5_MUXER || CONFIG_STREAMHASH_MUXER
static int hash_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
struct HashContext *c = s->priv_data;
- av_hash_update(c->hashes[0], pkt->data, pkt->size);
+ av_hash_update(c->hashes[c->per_stream ? pkt->stream_index : 0], pkt->data, pkt->size);
return 0;
}
static int hash_write_trailer(struct AVFormatContext *s)
{
struct HashContext *c = s->priv_data;
- char buf[AV_HASH_MAX_SIZE*2+128];
- snprintf(buf, sizeof(buf) - 200, "%s=", av_hash_get_name(c->hashes[0]));
-
- av_hash_final_hex(c->hashes[0], buf + strlen(buf), sizeof(buf) - strlen(buf));
- av_strlcatf(buf, sizeof(buf), "\n");
- avio_write(s->pb, buf, strlen(buf));
- avio_flush(s->pb);
+ int num_hashes = c->per_stream ? s->nb_streams : 1;
+ for (int i = 0; i < num_hashes; i++) {
+ char buf[AV_HASH_MAX_SIZE*2+128];
+ if (c->per_stream) {
+ snprintf(buf, sizeof(buf) - 200, "%d,%s=", i, av_hash_get_name(c->hashes[i]));
+ } else {
+ snprintf(buf, sizeof(buf) - 200, "%s=", av_hash_get_name(c->hashes[i]));
+ }
+ av_hash_final_hex(c->hashes[i], buf + strlen(buf), sizeof(buf) - strlen(buf));
+ av_strlcatf(buf, sizeof(buf), "\n");
+ avio_write(s->pb, buf, strlen(buf));
+ avio_flush(s->pb);
+ }
return 0;
}
@@ -112,7 +129,10 @@ static int hash_write_trailer(struct AVFormatContext *s)
static void hash_free(struct AVFormatContext *s)
{
struct HashContext *c = s->priv_data;
- av_hash_freep(&c->hashes[0]);
+ int num_hashes = c->per_stream ? s->nb_streams : 1;
+ for (int i = 0; i < num_hashes; i++) {
+ av_hash_freep(&c->hashes[i]);
+ }
av_freep(&c->hashes);
}
#endif
@@ -165,6 +185,49 @@ AVOutputFormat ff_md5_muxer = {
};
#endif
+#if CONFIG_STREAMHASH_MUXER
+static int streamhash_init(struct AVFormatContext *s)
+{
+ int res, i;
+ struct HashContext *c = s->priv_data;
+ c->per_stream = 1;
+ c->hashes = av_mallocz_array(s->nb_streams, sizeof(c->hashes));
+ if (!c->hashes)
+ return AVERROR(ENOMEM);
+ for (i = 0; i < s->nb_streams; i++) {
+ res = av_hash_alloc(&c->hashes[i], c->hash_name);
+ if (res < 0) {
+ hash_free(s);
+ return res;
+ }
+ av_hash_init(c->hashes[i]);
+ }
+ return 0;
+}
+
+static const AVClass streamhashenc_class = {
+ .class_name = "stream hash muxer",
+ .item_name = av_default_item_name,
+ .option = streamhash_options,
+ .version = LIBAVUTIL_VERSION_INT,
+};
+
+AVOutputFormat ff_streamhash_muxer = {
+ .name = "streamhash",
+ .long_name = NULL_IF_CONFIG_SMALL("Per-stream hash testing"),
+ .priv_data_size = sizeof(struct HashContext),
+ .audio_codec = AV_CODEC_ID_PCM_S16LE,
+ .video_codec = AV_CODEC_ID_RAWVIDEO,
+ .init = streamhash_init,
+ .write_packet = hash_write_packet,
+ .write_trailer = hash_write_trailer,
+ .deinit = hash_free,
+ .flags = AVFMT_VARIABLE_FPS | AVFMT_TS_NONSTRICT |
+ AVFMT_TS_NEGATIVE,
+ .priv_class = &streamhashenc_class,
+};
+#endif
+
#if CONFIG_FRAMEHASH_MUXER || CONFIG_FRAMEMD5_MUXER
static void framehash_print_extradata(struct AVFormatContext *s)
{
@@ -191,6 +254,7 @@ static int framehash_init(struct AVFormatContext *s)
{
int res;
struct HashContext *c = s->priv_data;
+ c->per_stream = 0;
c->hashes = av_mallocz_array(1, sizeof(c->hashes));
if (!c->hashes)
return AVERROR(ENOMEM);
diff --git a/libavformat/version.h b/libavformat/version.h
index edfa73fb97..bcd0408d28 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -32,8 +32,8 @@
// Major bumping may affect Ticket5467, 5421, 5451(compatibility with Chromium)
// Also please add any ticket numbers that you believe might be affected here
#define LIBAVFORMAT_VERSION_MAJOR 58
-#define LIBAVFORMAT_VERSION_MINOR 32
-#define LIBAVFORMAT_VERSION_MICRO 104
+#define LIBAVFORMAT_VERSION_MINOR 33
+#define LIBAVFORMAT_VERSION_MICRO 100
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
--
2.20.1
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