[vlc-devel] [PATCH] chromecast: use the Matroska muxer as it works better and allow more codec combinations

[Steve Lhomme]

On Wed, Oct 7, 2015 at 10:40 AM, Steve Lhomme <robux4 at videolabs.io> wrote:
> ---
>  modules/stream_out/chromecast/cast.cpp | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/modules/stream_out/chromecast/cast.cpp b/modules/stream_out/chromecast/cast.cpp
> index 488d97b..dd9562e 100644
> --- a/modules/stream_out/chromecast/cast.cpp
> +++ b/modules/stream_out/chromecast/cast.cpp
> @@ -186,8 +186,8 @@ vlc_module_begin ()
>      add_string(SOUT_CFG_PREFIX "ip", "", IP_TEXT, IP_LONGTEXT, false)
>      add_string(SOUT_CFG_PREFIX "target", "", TARGET_TEXT, TARGET_LONGTEXT, false)
>      add_integer(SOUT_CFG_PREFIX "http-port", HTTP_PORT, HTTP_PORT_TEXT, HTTP_PORT_LONGTEXT, false)
> -    add_string(SOUT_CFG_PREFIX "mux", "mp4stream", MUX_TEXT, MUX_LONGTEXT, false)
> -    add_string(SOUT_CFG_PREFIX "mime", "video/mp4", MIME_TEXT, MIME_LONGTEXT, false)
> +    add_string(SOUT_CFG_PREFIX "mux", "avformat{mux=matroska}", MUX_TEXT, MUX_LONGTEXT, false)
> +    add_string(SOUT_CFG_PREFIX "mime", "video/x-matroska", MIME_TEXT, MIME_LONGTEXT, false)
>
>  vlc_module_end ()


After investigating the stuttering I mentioned at VDD15, it turns out
the MP4 muxer is creating this. In addition it muxes the video frames
2x too fast. Resulting in playback distortion on the Chromecast.

When using avformat's muxer it works fine. Using Matroska also has the
advantage that the data can be sent without buffering much (dunno if
that's what the avformat muxer does).