[FFmpeg-devel] [PATCH]Lagarith: CODEC_CAP_DR1 ?

Baptiste Coudurier baptiste.coudurier
Sun Jan 9 23:23:20 CET 2011

On 1/9/11 2:02 PM, Reimar D?ffinger wrote:
> On Sun, Jan 09, 2011 at 01:39:49AM +0100, Luca Barbato wrote:
>> On 01/08/2011 11:09 PM, Carl Eugen Hoyos wrote:
>>> Attached patch is necessary to make FFmpeg's lagarith decoder work with 
>>> MPlayer.
>> what breaks otherwise?
> I'd like to know that as well, but I suspect that MPlayer dislikes that
> AFAICT the decoder does not set buffer_hints, which at least is suboptimal
> and should be fixed anyway.
> I think all that is necessary is adding
> c->pic.buffer_hints = FF_BUFFER_HINTS_VALID;
> since AFAICT the decoder does not do any reads at all from the buffer.
> Note that this is very useful to set, since this means a player could
> return a buffer in video ram that can be _very_ slow to read, whereas without
> the buffer hints it can't know that (it knows it is not a reference frame,
> but the decoder could still read data from the buffer while decoding a frame).

Well, it seems many decoders are kinda slacking regarding buffer hints,
AVFrame->reference field, so I'd say that verifying decoders and fix
everything regarding re/get_buffer would be great and really
appreciated. I'm not too familiar with buffer hints myself.

Also all intra only codec decoders should only set the fields
(FF_I_TYPE, key_frame, reference) once in decode_init, not for every
frame IMHO.

Key fingerprint                 8D77134D20CC9220201FC5DB0AC9325C5C1ABAAA
FFmpeg maintainer                                  http://www.ffmpeg.org

More information about the ffmpeg-devel mailing list