[vlc-devel] [PATCH] avformat : add an option to force a specific format

[Rafaël Carré]

Le 2012-02-16 09:14, Sébastien Escudier a écrit :
> Hi,
> 
> Why this patch ? 
> Because ffmpeg can demux mxpeg stream, but does not autodetect it (with
> ffplay you must add -f mxg to read the stream).
> 
> So I added an option to force a ffmpeg format, like the ffmpeg-codec
> option we already have.
> 
> Is it ok ?

OK with me, I think it's a good idea.

> Regards,
> Sébastien.
> 
> 
> 
> 0001-avformat-add-an-option-to-force-a-specific-format.patch
> 
> 
> From 01f88016d0b26b79509ac197de1e7446e4cf1638 Mon Sep 17 00:00:00 2001
> From: =?UTF-8?q?S=C3=A9bastien=20Escudier?= <sebastien-devel at celeos.eu>
> Date: Thu, 16 Feb 2012 15:08:33 +0100
> Subject: [PATCH] avformat : add an option to force a specific format
> 
> ---
>  modules/demux/avformat/avformat.c |    4 ++++
>  modules/demux/avformat/demux.c    |   11 +++++++++--
>  2 files changed, 13 insertions(+), 2 deletions(-)
> 
> diff --git a/modules/demux/avformat/avformat.c b/modules/demux/avformat/avformat.c
> index 70ce57f..18f8640 100644
> --- a/modules/demux/avformat/avformat.c
> +++ b/modules/demux/avformat/avformat.c
> @@ -32,6 +32,9 @@
>  
>  #include "avformat.h"
>  
> +#define FORMAT_TEXT N_( "Format name" )
> +#define FORMAT_LONGTEXT N_( "Internal libavcodec format name" )
> +
>  vlc_module_begin ()
>  #endif /* MERGE_FFMPEG */
>      add_shortcut( "ffmpeg", "avformat" )
> @@ -41,6 +44,7 @@ vlc_module_begin ()
>      set_shortname( N_("Avformat") )
>      set_capability( "demux", 2 )
>      set_callbacks( OpenDemux, CloseDemux )
> +    add_string( "ffmpeg-format", NULL, FORMAT_TEXT, FORMAT_LONGTEXT, true )
>  
>  #ifdef ENABLE_SOUT
>      /* mux submodule */
> diff --git a/modules/demux/avformat/demux.c b/modules/demux/avformat/demux.c
> index d346f0f..0704104 100644
> --- a/modules/demux/avformat/demux.c
> +++ b/modules/demux/avformat/demux.c
> @@ -112,7 +112,7 @@ int OpenDemux( vlc_object_t *p_this )
>      demux_t       *p_demux = (demux_t*)p_this;
>      demux_sys_t   *p_sys;
>      AVProbeData   pd;
> -    AVInputFormat *fmt;
> +    AVInputFormat *fmt = NULL;
>      unsigned int  i;
>      int64_t       i_start_time = -1;
>      bool          b_can_seek;
> @@ -141,8 +141,15 @@ int OpenDemux( vlc_object_t *p_this )
>      av_register_all(); /* Can be called several times */
>      vlc_avcodec_unlock();
>  
> +    char *psz_format = var_InheritString( p_this, "ffmpeg-format" );
> +    if( psz_format && *psz_format )

var_InheritString returns NULL if the string is empty (non NULL but "")
so you could skip the && *psz_format

> +    {
> +        if( fmt = av_find_input_format(psz_format) )
> +            msg_Dbg( p_demux, "forcing format: %s", fmt->name );
> +    }
> +
>      /* Guess format */
> -    if( !( fmt = av_probe_input_format( &pd, 1 ) ) )
> +    if( !fmt && !( fmt = av_probe_input_format( &pd, 1 ) ) )
>      {
>          msg_Dbg( p_demux, "couldn't guess format" );
>          free( psz_url );
> -- 1.7.0.4

You're leaking psz_format.