sd_lavc: strictly letter-box PGS subtitles

Getting subtitle scaling and positioning right even if there are video
filters, which completely change the image (like cropping), doesn't seem
to have a single, correct solution. To some degree, the results are
arbitrary, so we may as well do what is most useful to the user.

In this case, if the PGS resolution aspect ratio and the video output
aspect ratio mismatch, letter-box it, instead of stretching the subs
over the video frame. (This will require additional fixes, should it
turn out that there are PGS subtitles which are stretched by design.)

Fixes #1205.
This commit is contained in:
wm4 2014-10-21 11:37:32 +02:00
parent 38420eb49e
commit bcc3d72995
3 changed files with 9 additions and 4 deletions

View File

@ -344,7 +344,7 @@ void mp_nav_get_highlight(void *priv, struct mp_osd_res res,
if (out_imgs->num_parts) {
out_imgs->parts = nav->outputs;
out_imgs->format = SUBBITMAP_RGBA;
osd_rescale_bitmaps(out_imgs, sizes[0], sizes[1], res, -1);
osd_rescale_bitmaps(out_imgs, sizes[0], sizes[1], res, 0);
}
pthread_mutex_unlock(&nav->osd_lock);

View File

@ -466,8 +466,9 @@ struct mp_osd_res osd_get_vo_res(struct osd_state *osd, int obj)
// Position the subbitmaps in imgs on the screen. Basically, this fits the
// subtitle canvas (of size frame_w x frame_h) onto the screen, such that it
// fills the whole video area (especially if the video is magnified, e.g. on
// fullscreen). If compensate_par is given, adjust the way the subtitles are
// "stretched" on the screen, and letter-box the result.
// fullscreen). If compensate_par is >0, adjust the way the subtitles are
// "stretched" on the screen, and letter-box the result. If compensate_par
// is <0, strictly letter-box the subtitles. If it is 0, stretch them.
void osd_rescale_bitmaps(struct sub_bitmaps *imgs, int frame_w, int frame_h,
struct mp_osd_res res, double compensate_par)
{
@ -475,6 +476,8 @@ void osd_rescale_bitmaps(struct sub_bitmaps *imgs, int frame_w, int frame_h,
int vidh = res.h - res.mt - res.mb;
double xscale = (double)vidw / frame_w;
double yscale = (double)vidh / frame_h;
if (compensate_par < 0)
compensate_par = xscale / yscale / res.display_par;
if (compensate_par > 0) {
if (compensate_par > 1.0) {
xscale /= compensate_par;

View File

@ -292,7 +292,7 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res d, double pts,
priv->displayed_id = current->id;
res->format = SUBBITMAP_INDEXED;
double video_par = -1;
double video_par = 0;
if (priv->avctx->codec_id == AV_CODEC_ID_DVD_SUBTITLE &&
opts->stretch_dvd_subs) {
// For DVD subs, try to keep the subtitle PAR at display PAR.
@ -302,6 +302,8 @@ static void get_bitmaps(struct sd *sd, struct mp_osd_res d, double pts,
if (isnormal(par))
video_par = par;
}
if (priv->avctx->codec_id == AV_CODEC_ID_HDMV_PGS_SUBTITLE)
video_par = -1;
int insize[2];
get_resolution(sd, insize);
osd_rescale_bitmaps(res, insize[0], insize[1], d, video_par);