sdl: fix aspect ratio computations.

The rounding was wrong due to incorrect ue of floats,
changed to rationals and av_rescale.

The results were not properly passed to SDL.
This commit is contained in:
Nicolas George 2012-06-09 21:03:18 +02:00
parent 3ff6b1a2b3
commit 4adf5dfadb
2 changed files with 32 additions and 17 deletions

View File

@ -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@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

View File

@ -38,6 +38,7 @@ typedef struct {
char *icon_title;
int window_width, window_height; /**< size of the window */
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);
return 0;
}