[FFmpeg-devel] [PATCH 3/3] sdl: fix aspect ratio computations.
Stefano Sabatini
stefasab at gmail.com
Sat Jun 9 23:55:46 CEST 2012
On date Saturday 2012-06-09 21:26:52 +0200, Nicolas George encoded:
> The rounding was wrong due to incorrect ue of floats,
ue -> use
> changed to rationals and av_rescale.
>
> The results were not properly passed to SDL.
>
> Signed-off-by: Nicolas George <nicolas.george at normalesup.org>
> ---
> doc/outdevs.texi | 3 ++-
> libavdevice/sdl.c | 48 +++++++++++++++++++++++++++++++-----------------
> 2 files changed, 33 insertions(+), 18 deletions(-)
>
> diff --git a/doc/outdevs.texi b/doc/outdevs.texi
> index 8de4fe6..8034a22 100644
> --- a/doc/outdevs.texi
> +++ b/doc/outdevs.texi
> @@ -55,7 +55,8 @@ to the same value of @var{window_title}.
> @item window_size
> Set the SDL window size, can be a string of the form
> @var{width}x at var{height} or a video size abbreviation.
> -If not specified it defaults to the size of the input video.
> +If not specified it defaults to the size of the input video,
> +downscaled according to the aspect ratio.
> @end table
>
> @subsection Examples
> diff --git a/libavdevice/sdl.c b/libavdevice/sdl.c
> index c80d41c..9c57f73 100644
> --- a/libavdevice/sdl.c
> +++ b/libavdevice/sdl.c
> @@ -36,8 +36,9 @@ typedef struct {
> SDL_Overlay *overlay;
> char *window_title;
> char *icon_title;
> - int window_width, window_height; /**< size of the window */
> + int window_width, window_height; /**< size of the window */
spurious
> int overlay_width, overlay_height; /**< size of the video in the window */
> + int overlay_x, overlay_y;
> int overlay_fmt;
> int sdl_was_already_inited;
> } SDLContext;
> @@ -73,7 +74,7 @@ static int sdl_write_header(AVFormatContext *s)
> SDLContext *sdl = s->priv_data;
> AVStream *st = s->streams[0];
> AVCodecContext *encctx = st->codec;
> - float sar, dar; /* sample and display aspect ratios */
> + AVRational sar, dar; /* sample and display aspect ratios */
> int i, ret;
>
> if (!sdl->window_title)
> @@ -119,21 +120,34 @@ static int sdl_write_header(AVFormatContext *s)
> }
>
> /* compute overlay width and height from the codec context information */
> - sar = st->sample_aspect_ratio.num ? av_q2d(st->sample_aspect_ratio) : 1;
> - dar = sar * (float)encctx->width / (float)encctx->height;
> + sar = st->sample_aspect_ratio.num ? st->sample_aspect_ratio : (AVRational){ 1, 1 };
> + dar = av_mul_q(sar, (AVRational){ encctx->width, encctx->height });
>
> /* we suppose the screen has a 1/1 sample aspect ratio */
> - sdl->overlay_height = encctx->height;
> - sdl->overlay_width = ((int)rint(sdl->overlay_height * dar));
> - if (sdl->overlay_width > encctx->width) {
> - sdl->overlay_width = encctx->width;
> - sdl->overlay_height = ((int)rint(sdl->overlay_width / dar));
> - }
> -
> - if (!sdl->window_width || !sdl->window_height) {
> + if (sdl->window_width && sdl->window_height) {
> + /* fit in the window */
> + if (av_cmp_q(dar, (AVRational){ sdl->window_width, sdl->window_height }) > 0) {
> + /* fit in width */
> + sdl->overlay_width = sdl->window_width;
> + sdl->overlay_height = av_rescale(sdl->overlay_width, dar.den, dar.num);
> + } else {
> + /* fit in height */
> + sdl->overlay_height = sdl->window_height;
> + sdl->overlay_width = av_rescale(sdl->overlay_height, dar.num, dar.den);
> + }
> + } else {
> + if (sar.num > sar.den) {
> + sdl->overlay_width = encctx->width;
> + sdl->overlay_height = av_rescale(sdl->overlay_width, dar.den, dar.num);
> + } else {
> + sdl->overlay_height = encctx->height;
> + sdl->overlay_width = av_rescale(sdl->overlay_height, dar.num, dar.den);
> + }
> sdl->window_width = sdl->overlay_width;
> sdl->window_height = sdl->overlay_height;
> }
> + sdl->overlay_x = (sdl->window_width - sdl->overlay_width ) / 2;
> + sdl->overlay_y = (sdl->window_height - sdl->overlay_height) / 2;
>
> SDL_WM_SetCaption(sdl->window_title, sdl->icon_title);
> sdl->surface = SDL_SetVideoMode(sdl->window_width, sdl->window_height,
> @@ -154,9 +168,9 @@ static int sdl_write_header(AVFormatContext *s)
> goto fail;
> }
>
> - av_log(s, AV_LOG_INFO, "w:%d h:%d fmt:%s sar:%f -> w:%d h:%d\n",
> - encctx->width, encctx->height, av_get_pix_fmt_name(encctx->pix_fmt), sar,
> - sdl->window_width, sdl->window_height);
> + av_log(s, AV_LOG_INFO, "w:%d h:%d fmt:%s sar:%d/%d -> w:%d h:%d\n",
> + encctx->width, encctx->height, av_get_pix_fmt_name(encctx->pix_fmt), sar.num, sar.den,
> + sdl->overlay_width, sdl->overlay_height);
> return 0;
>
> fail:
> @@ -168,7 +182,7 @@ static int sdl_write_packet(AVFormatContext *s, AVPacket *pkt)
> {
> SDLContext *sdl = s->priv_data;
> AVCodecContext *encctx = s->streams[0]->codec;
> - SDL_Rect rect = { 0, 0, sdl->window_width, sdl->window_height };
> + SDL_Rect rect = { sdl->overlay_x, sdl->overlay_y, sdl->overlay_width, sdl->overlay_height };
> AVPicture pict;
> int i;
>
> @@ -184,7 +198,7 @@ static int sdl_write_packet(AVFormatContext *s, AVPacket *pkt)
> SDL_DisplayYUVOverlay(sdl->overlay, &rect);
> SDL_UnlockYUVOverlay(sdl->overlay);
>
> - SDL_UpdateRect(sdl->surface, 0, 0, sdl->overlay_width, sdl->overlay_height);
> + SDL_UpdateRect(sdl->surface, rect.x, rect.y, rect.w, rect.h);
Should be OK if tested, thanks.
--
FFmpeg = Fundamentalist and Fundamental MultiPurpose Enlightened Gadget
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