[FFmpeg-devel] [PATCH v2 3/3] avformat/hashenc: add streamhash muxer
James Almer
jamrial at gmail.com
Wed Sep 11 17:08:01 EEST 2019
On 9/11/2019 10:34 AM, Moritz Barsnick wrote:
> 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);
No need to call this. It's done automatically by the generic code when
this function returns an error.
> + 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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