[FFmpeg-devel] [PATCH 2/2] AST demuxer

Michael Niedermayer michaelni at gmx.at
Sat Nov 17 18:56:39 CET 2012


On Thu, Nov 15, 2012 at 08:42:19PM +0000, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  doc/general.texi         |   2 +
>  libavformat/Makefile     |   1 +
>  libavformat/allformats.c |   1 +
>  libavformat/ast.c        | 115 +++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 119 insertions(+)
>  create mode 100644 libavformat/ast.c
> 
> diff --git a/doc/general.texi b/doc/general.texi
> index 28f813e..951df8e 100644
> --- a/doc/general.texi
> +++ b/doc/general.texi
> @@ -148,6 +148,8 @@ library:
>  @item Apple HTTP Live Streaming @tab   @tab X
>  @item Artworx Data Format       @tab   @tab X
>  @item ASF                       @tab X @tab X
> + at item AST                       @tab   @tab X
> +    @tab Used on the Nintendo Wii.
>  @item AVI                       @tab X @tab X
>  @item AVISynth                  @tab   @tab X
>  @item AVR                       @tab   @tab X
> diff --git a/libavformat/Makefile b/libavformat/Makefile
> index cf3aae2..136ada8 100644
> --- a/libavformat/Makefile
> +++ b/libavformat/Makefile
> @@ -50,6 +50,7 @@ OBJS-$(CONFIG_ASF_DEMUXER)               += asfdec.o asf.o asfcrypt.o \
>  OBJS-$(CONFIG_ASF_MUXER)                 += asfenc.o asf.o
>  OBJS-$(CONFIG_ASS_DEMUXER)               += assdec.o
>  OBJS-$(CONFIG_ASS_MUXER)                 += assenc.o
> +OBJS-$(CONFIG_AST_DEMUXER)               += ast.o
>  OBJS-$(CONFIG_AU_DEMUXER)                += au.o pcm.o
>  OBJS-$(CONFIG_AU_MUXER)                  += au.o
>  OBJS-$(CONFIG_AVI_DEMUXER)               += avidec.o
> diff --git a/libavformat/allformats.c b/libavformat/allformats.c
> index 88b4e1b..d08c134 100644
> --- a/libavformat/allformats.c
> +++ b/libavformat/allformats.c
> @@ -64,6 +64,7 @@ void av_register_all(void)
>      REGISTER_DEMUXER  (APE, ape);
>      REGISTER_MUXDEMUX (ASF, asf);
>      REGISTER_MUXDEMUX (ASS, ass);
> +    REGISTER_DEMUXER  (AST, ast);
>      REGISTER_MUXER    (ASF_STREAM, asf_stream);
>      REGISTER_MUXDEMUX (AU, au);
>      REGISTER_MUXDEMUX (AVI, avi);
> diff --git a/libavformat/ast.c b/libavformat/ast.c
> new file mode 100644
> index 0000000..ed55e02
> --- /dev/null
> +++ b/libavformat/ast.c
> @@ -0,0 +1,115 @@
> +/*
> + * AST demuxer
> + * Copyright (c) 2012 Paul B Mahol
> + *
> + * 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/channel_layout.h"
> +#include "libavutil/intreadwrite.h"
> +#include "avformat.h"
> +#include "internal.h"
> +
> +static int ast_probe(AVProbeData *p)
> +{
> +    if (AV_RL32(p->buf) == MKTAG('S', 'T', 'R', 'M'))
> +        return AVPROBE_SCORE_MAX / 2;
> +    return 0;
> +}
> +
> +static int ast_read_header(AVFormatContext *s)
> +{
> +    int codec;
> +    AVStream *st;
> +
> +    st = avformat_new_stream(s, NULL);
> +    if (!st)
> +        return AVERROR(ENOMEM);
> +
> +    avio_skip(s->pb, 8);
> +    codec = avio_rb16(s->pb);
> +    switch (codec) {
> +    case 1:
> +        st->codec->codec_id = AV_CODEC_ID_PCM_S16BE_PLANAR;
> +        break;
> +    default:
> +        av_log(s, AV_LOG_ERROR, "unsupported codec %d\n", codec);
> +    }
> +
> +    avio_skip(s->pb, 2);
> +
> +    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
> +    st->codec->channels = avio_rb16(s->pb);
> +    if (!st->codec->channels)
> +        return AVERROR_INVALIDDATA;
> +
> +    if (st->codec->channels == 2)
> +        st->codec->channel_layout = AV_CH_LAYOUT_STEREO;
> +    else if (st->codec->channels == 4)
> +        st->codec->channel_layout = AV_CH_LAYOUT_4POINT0;
> +
> +    avio_skip(s->pb, 2);
> +    st->codec->sample_rate = avio_rb32(s->pb);
> +    st->start_time         = 0;
> +    st->duration           = avio_rb32(s->pb);
> +    avio_skip(s->pb, 40);
> +    avpriv_set_pts_info(st, 64, 1, st->codec->sample_rate);

the sample rate could by checked for <= 0 before use

rest LGTM 

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

I am the wisest man alive, for I know one thing, and that is that I know
nothing. -- Socrates
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