[FFmpeg-devel] [PATCH] lavd/sdl: add event handler thread

[Lukasz M]

On 24 November 2013 20:12, Stefano Sabatini <stefasab at gmail.com> wrote:

> Experimental and partially untested, meant to address ticket #1743 and
> #1744.
> ---
>  libavdevice/sdl.c | 115
> +++++++++++++++++++++++++++++++++++++++++++++---------
>  1 file changed, 96 insertions(+), 19 deletions(-)
>
> +static int event_thread(void *arg)
> +{
> +    AVFormatContext *s = arg;
> +    SDLContext *sdl = s->priv_data;
> +    int flags = SDL_SWSURFACE | sdl->window_fullscreen ? SDL_FULLSCREEN :
> 0;
> +    AVStream *st = s->streams[0];
> +    AVCodecContext *encctx = st->codec;
> +
> +    /* initialization */
> +    SDL_WM_SetCaption(sdl->window_title, sdl->icon_title);
> +    sdl->surface = SDL_SetVideoMode(sdl->window_width, sdl->window_height,
> +                                    24, flags);
> +    if (!sdl->surface) {
> +        av_log(sdl, AV_LOG_ERROR, "Unable to set video mode: %s\n",
> SDL_GetError());
> +        return AVERROR(EINVAL);
>

You will have a deadlock, sdl->inited is never set to 1 and
sdl_write_header will wait forever. The same below.
Returned values are send to nowhere, but no clue if they can be handled.
Setting sdl->quit to 1 and signal sdl->init_event_cond may help.
In sdl_write_header you may check if quit is set and return with error.


> +    }
> +
> +    sdl->overlay = SDL_CreateYUVOverlay(encctx->width, encctx->height,
> +                                        sdl->overlay_fmt, sdl->surface);
> +    if (!sdl->overlay || sdl->overlay->pitches[0] < encctx->width) {
> +        av_log(s, AV_LOG_ERROR,
> +               "SDL does not support an overlay with size of %dx%d
> pixels\n",
> +               encctx->width, encctx->height);
> +        return AVERROR(EINVAL);
> +    }
> +
> +    av_log(s, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s -> w:%d h:%d\n",
> +           encctx->width, encctx->height,
> av_get_pix_fmt_name(encctx->pix_fmt),
> +           sdl->overlay_width, sdl->overlay_height);
> +
> +    SDL_LockMutex(sdl->mutex);
> +    sdl->inited = 1;
> +    SDL_CondSignal(sdl->init_event_cond);
> +    SDL_UnlockMutex(sdl->mutex);
>

You can unlock mutex before signaling.


> +    /* event loop */
> +    while (!sdl->quit) {
> +        SDL_Event event;
> +        SDL_PumpEvents();
> +        if (SDL_PeepEvents(&event, 1, SDL_GETEVENT, SDL_ALLEVENTS) <= 0) {
> +            /* fixme: make this customizable? */
> +            av_usleep(1000.0);
> +            continue;
> +        }
> +
> +        switch (event.type) {
> +        case SDL_KEYDOWN:
> +            switch (event.key.keysym.sym) {
> +            case SDLK_ESCAPE:
> +            case SDLK_q:
> +                sdl->quit = 1;
> +                break;
> +            }
> +            break;
> +        case SDL_QUIT:
> +            sdl->quit = 1;
> +            break;
> +        default:
> +            break;
> +        }
> +    }
> +
> +    return 0;
> +}
> +
>