[FFmpeg-devel] [PATCH 2/6] Frame-based multithreading framework using pthreads

[Ronald S. Bultje]

Hi,

On Sat, Feb 5, 2011 at 1:35 PM, Reimar D?ffinger
<Reimar.Doeffinger at gmx.de> wrote:
> On Sat, Feb 05, 2011 at 12:28:25AM -0500, Alexander Strange wrote:
>> @@ -1238,6 +1255,10 @@ typedef struct AVCodecContext {
>> ? ? ? * decoder to draw a horizontal band. It improves cache usage. Not
>> ? ? ? * all codecs can do that. You must check the codec capabilities
>> ? ? ? * beforehand.
>> + ? ? * When multithreading is used, it may be called from multiple threads
>> + ? ? * at the same time; threads might draw different parts of the same AVFrame,
>> + ? ? * or multiple AVFrame, and there is no guarantee that slices will be drawn
>> + ? ? * in order.
>
> I think this is _mostly_ the same as before, so my comments should probably
> not be considered objections.
[..]
> The same applies to dr1 really, since e.g. many OpenGL implementations have
> issues with multiple threads, even when reentracy is not required.

So, probably silly question, but have people reported such issues? I
mean, as you say, H264 has done slice-based MT forever afaics, so it
seems to me if there was an issue, people would've noticed it in
mplayer (or so I hope).

Ronald