FFmpeg/libavformat/hashenc.c

/*
 * Hash/MD5 encoder (for codec/format testing)
 * Copyright (c) 2009 Reimar Döffinger, based on crcenc (c) 2002 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "libavutil/avassert.h"
#include "libavutil/avstring.h"
#include "libavutil/hash.h"
#include "libavutil/opt.h"
#include "avformat.h"
#include "internal.h"

struct HashContext {
    const AVClass *avclass;
    struct AVHashContext *hash;
    char *hash_name;
    int format_version;
};

static void hash_finish(struct AVFormatContext *s, char *buf)
{
    struct HashContext *c = s->priv_data;
    uint8_t hash[AV_HASH_MAX_SIZE];
    int i, offset = strlen(buf);
    int len = av_hash_get_size(c->hash);
    av_assert0(len > 0 && len <= sizeof(hash));
    av_hash_final(c->hash, hash);
    for (i = 0; i < len; i++) {
        snprintf(buf + offset, 3, "%02"PRIx8, hash[i]);
        offset += 2;
    }
    buf[offset] = '\n';
    buf[offset+1] = 0;

    avio_write(s->pb, buf, strlen(buf));
    avio_flush(s->pb);
}

#define OFFSET(x) offsetof(struct HashContext, x)
#define ENC AV_OPT_FLAG_ENCODING_PARAM
#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 = "sha256"}, 0, 0, ENC },
    { "format_version", "file format version", OFFSET(format_version), AV_OPT_TYPE_INT, {.i64 = 1}, 1, 2, ENC },
    { NULL },
};
#endif

#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, 2, ENC },
    { NULL },
};
#endif

#if CONFIG_HASH_MUXER || CONFIG_MD5_MUXER
static int hash_write_header(struct AVFormatContext *s)
{
    struct HashContext *c = s->priv_data;
    int res = av_hash_alloc(&c->hash, c->hash_name);
    if (res < 0)
        return res;
    av_hash_init(c->hash);
    return 0;
}

static int hash_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
    struct HashContext *c = s->priv_data;
    av_hash_update(c->hash, pkt->data, pkt->size);
    return 0;
}

static int hash_write_trailer(struct AVFormatContext *s)
{
    struct HashContext *c = s->priv_data;
    char buf[256];
    av_strlcpy(buf, av_hash_get_name(c->hash), sizeof(buf) - 200);
    av_strlcat(buf, "=", sizeof(buf) - 200);

    hash_finish(s, buf);

    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",
    .long_name         = NULL_IF_CONFIG_SMALL("MD5 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        = &md5enc_class,
};
#endif

#if CONFIG_FRAMEHASH_MUXER || CONFIG_FRAMEMD5_MUXER
static void framehash_print_extradata(struct AVFormatContext *s)
{
    int i;

    for (i = 0; i < s->nb_streams; i++) {
        AVStream *st = s->streams[i];
        AVCodecParameters *par = st->codecpar;
        if (par->extradata) {
            struct HashContext *c = s->priv_data;
            char buf[AV_HASH_MAX_SIZE*2+1];

            avio_printf(s->pb, "#extradata %d, %31d, ", i, par->extradata_size);
            av_hash_init(c->hash);
            av_hash_update(c->hash, par->extradata, par->extradata_size);
            av_hash_final_hex(c->hash, buf, sizeof(buf));
            avio_write(s->pb, buf, strlen(buf));
            avio_printf(s->pb, "\n");
        }
    }
}

static int framehash_write_header(struct AVFormatContext *s)
{
    struct HashContext *c = s->priv_data;
    int res = av_hash_alloc(&c->hash, c->hash_name);
    if (res < 0)
        return res;
    avio_printf(s->pb, "#format: frame checksums\n");
    avio_printf(s->pb, "#version: %d\n", c->format_version);
    avio_printf(s->pb, "#hash: %s\n", av_hash_get_name(c->hash));
    if (c->format_version > 1)
        framehash_print_extradata(s);
    ff_framehash_write_header(s, c->format_version);
    avio_printf(s->pb, "#stream#, dts,        pts, duration,     size, hash\n");
    return 0;
}

static int framehash_write_packet(struct AVFormatContext *s, AVPacket *pkt)
{
    struct HashContext *c = s->priv_data;
    char buf[256];
    av_hash_init(c->hash);
    av_hash_update(c->hash, pkt->data, pkt->size);

    snprintf(buf, sizeof(buf) - 64, "%d, %10"PRId64", %10"PRId64", %8"PRId64", %8d, ",
             pkt->stream_index, pkt->dts, pkt->pts, pkt->duration, pkt->size);
    hash_finish(s, buf);
    return 0;
}

static int framehash_write_trailer(struct AVFormatContext *s)
{
    struct HashContext *c = s->priv_data;
    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,
    .option     = md5_options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVOutputFormat ff_framemd5_muxer = {
    .name              = "framemd5",
    .long_name         = NULL_IF_CONFIG_SMALL("Per-frame MD5 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        = &framemd5_class,
};
#endif