[FFmpeg-devel] [PATCH 3/3] RedSpark demuxer

Michael Niedermayer michaelni at gmx.at
Mon May 6 11:30:27 CEST 2013


On Mon, Apr 22, 2013 at 06:27:09AM -0300, James Almer wrote:
> 
> Signed-off-by: James Almer <jamrial at gmail.com>
> ---
>  Changelog                |   1 +
>  doc/general.texi         |   1 +
>  libavformat/Makefile     |   1 +
>  libavformat/allformats.c |   1 +
>  libavformat/redspark.c   | 184 +++++++++++++++++++++++++++++++++++++++++++++++
>  libavformat/version.h    |   2 +-
>  6 files changed, 189 insertions(+), 1 deletion(-)
>  create mode 100644 libavformat/redspark.c
> 
> diff --git a/Changelog b/Changelog
> index 912110d..ed20459 100644
> --- a/Changelog
> +++ b/Changelog
> @@ -31,6 +31,7 @@ version <next>:
>  - asetrate filter
>  - interleave filter
>  - RSD demuxer
> +- RedSpark demuxer
>  
>  
>  version 1.2:
> diff --git a/doc/general.texi b/doc/general.texi
> index 8b98d51..13f56ee 100644
> --- a/doc/general.texi
> +++ b/doc/general.texi
> @@ -346,6 +346,7 @@ library:
>  @item RDT                       @tab   @tab X
>  @item REDCODE R3D               @tab   @tab X
>      @tab File format used by RED Digital cameras, contains JPEG 2000 frames and PCM audio.
> + at item RedSpark                  @tab   @tab X
>  @item RealMedia                 @tab X @tab X
>  @item Redirector                @tab   @tab X
>  @item Renderware TeXture Dictionary @tab   @tab X
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index dbc0e41..eda9f2d 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -304,6 +304,7 @@ OBJS-$(CONFIG_R3D_DEMUXER)               += r3d.o
>  OBJS-$(CONFIG_RAWVIDEO_DEMUXER)          += rawvideodec.o
>  OBJS-$(CONFIG_RAWVIDEO_MUXER)            += rawenc.o
>  OBJS-$(CONFIG_REALTEXT_DEMUXER)          += realtextdec.o subtitles.o
> +OBJS-$(CONFIG_REDSPARK_DEMUXER)          += redspark.o
>  OBJS-$(CONFIG_RL2_DEMUXER)               += rl2.o
>  OBJS-$(CONFIG_RM_DEMUXER)                += rmdec.o rm.o rmsipr.o
>  OBJS-$(CONFIG_RM_MUXER)                  += rmenc.o rm.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index e18351b..8d134f2 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -230,6 +230,7 @@ void av_register_all(void)
>      REGISTER_DEMUXER (R3D,              r3d);
>      REGISTER_MUXDEMUX(RAWVIDEO,         rawvideo);
>      REGISTER_DEMUXER (REALTEXT,         realtext);
> +    REGISTER_DEMUXER (REDSPARK,         redspark);
>      REGISTER_DEMUXER (RL2,              rl2);
>      REGISTER_MUXDEMUX(RM,               rm);
>      REGISTER_MUXDEMUX(ROQ,              roq);
> diff --git a/libavformat/redspark.c b/libavformat/redspark.c
> new file mode 100644
> index 0000000..d37aba0
> --- /dev/null
> +++ b/libavformat/redspark.c
> @@ -0,0 +1,184 @@
> +/*
> + * RedSpark demuxer
> + * Copyright (c) 2013 James Almer
> + *
> + * 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 "libavcodec/bytestream.h"
> +#include "libavutil/intreadwrite.h"
> +#include "avformat.h"
> +#include "avio.h"
> +#include "internal.h"
> +
> +#define HEADER_SIZE 4096
> +
> +typedef struct RedSparkContext {
> +    int         samples_count;
> +    uint8_t     *table;
> +} RedSparkContext;
> +
> +static int redspark_probe(AVProbeData *p)
> +{
> +    uint32_t key, data;
> +    uint8_t header[8];
> +
> +    /* Decrypt first 8 bytes of the header */
> +    data = AV_RB32(p->buf);
> +    data = data ^ (key = data ^ 0x52656453);
> +    AV_WB32(header, data);
> +    key = (key << 11) | (key >> 21);
> +
> +    data = AV_RB32(p->buf + 4) ^ (((key << 3) | (key >> 29)) + key);
> +    AV_WB32(header + 4, data);
> +
> +    if (!memcmp(header, "RedSpark", 8))
> +        return AVPROBE_SCORE_MAX;
> +
> +    return 0;
> +}
> +
> +static int redspark_close(AVFormatContext *s)
> +{
> +    RedSparkContext *redspark = s->priv_data;
> +
> +    av_freep(&redspark->table);
> +
> +    return 0;
> +}
> +
> +static int redspark_read_header(AVFormatContext *s)
> +{
> +    AVIOContext *pb = s->pb;
> +    RedSparkContext *redspark = s->priv_data;
> +    AVCodecContext *codec;
> +    GetByteContext gbc;
> +    int i, coef_off, ret = 0;
> +    uint32_t key, data;
> +    uint8_t *header, *pbc;
> +    AVStream *st;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +    codec = st->codec;
> +
> +    header = av_malloc(HEADER_SIZE);
> +    if (!header)
> +        return AVERROR(ENOMEM);
> +    pbc = header;
> +
> +    /* Decrypt header */
> +    data = avio_rb32(pb);
> +    data = data ^ (key = data ^ 0x52656453);
> +    bytestream_put_be32(&pbc, data);
> +    key = (key << 11) | (key >> 21);
> +
> +    for (i = 0; i < HEADER_SIZE - 4; i += 4) {
> +        data = avio_rb32(pb) ^ (key = ((key << 3) | (key >> 29)) + key);
> +        bytestream_put_be32(&pbc, data);
> +    }
> +
> +    codec->codec_id    = AV_CODEC_ID_ADPCM_THP;
> +    codec->codec_type  = AVMEDIA_TYPE_AUDIO;
> +
> +    bytestream2_init(&gbc, header, HEADER_SIZE);
> +    bytestream2_seek(&gbc, 0x3c, SEEK_SET);
> +    codec->sample_rate = bytestream2_get_be32u(&gbc);
> +    if (codec->sample_rate <= 0 || codec->sample_rate > 96000) {
> +        av_log(s, AV_LOG_ERROR, "Invalid sample rate: %d\n", codec->sample_rate);
> +        ret = AVERROR_INVALIDDATA;
> +        goto end;
> +    }
> +
> +    st->duration = bytestream2_get_be32u(&gbc) * 14;
> +    redspark->samples_count = 0;
> +    bytestream2_skipu(&gbc, 10);
> +    codec->channels = bytestream2_get_byteu(&gbc);
> +    if (!codec->channels) {
> +        ret = AVERROR_INVALIDDATA;
> +        goto end;
> +    }
> +
> +    coef_off = 0x54 + codec->channels * 8;
> +    if (bytestream2_get_byteu(&gbc)) // Loop flag
> +        coef_off += 16;
> +
> +    redspark->table = av_malloc(32 * codec->channels);
> +    if (!redspark->table) {
> +        ret = AVERROR(ENOMEM);
> +        goto end;
> +    }
> +
> +    /* Get the ADPCM table */
> +    bytestream2_seek(&gbc, coef_off, SEEK_SET);
> +    for (i = 0; i < codec->channels; i++) {
> +        if (bytestream2_get_bufferu(&gbc, redspark->table + i * 32, 32) != 32) {
> +            ret = AVERROR_INVALIDDATA;
> +            redspark_close(s);
> +            goto end;
> +        }
> +        bytestream2_skipu(&gbc, 14);
> +    }
> +
> +    avpriv_set_pts_info(st, 64, 1, codec->sample_rate);
> +
> +end:
> +    av_freep(&header);
> +
> +    return ret;
> +}
> +
> +static int redspark_read_packet(AVFormatContext *s, AVPacket *pkt)
> +{
> +    AVCodecContext *codec = s->streams[0]->codec;
> +    RedSparkContext *redspark = s->priv_data;
> +    uint32_t size = 8 * codec->channels;
> +    int ret;
> +
> +    if (url_feof(s->pb) || redspark->samples_count == s->streams[0]->duration)
> +        return AVERROR_EOF;
> +

> +    if ((ret = av_new_packet(pkt, size)) < 0)
> +        return ret;
> +    if (!av_packet_new_side_data(pkt, AV_PKT_DATA_NEW_EXTRADATA, 32 * codec->channels))
> +        return AVERROR(ENOMEM);
> +
> +    memcpy(pkt->side_data[0].data, redspark->table, 32 * codec->channels);

As the data is truly global and doesnt change, this too should
probably use AVCodecContext.extradata
I suspect this will also simplify the code

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

If you think the mosad wants you dead since a long time then you are either
wrong or dead since a long time.
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