From 5c219e289e7f3a7e369f692053bd0c1d35937a33 Mon Sep 17 00:00:00 2001 From: Clément Bœsch Date: Sun, 8 Feb 2015 12:38:06 +0100 Subject: avcodec/srtdec: attempt to correct SubRip positioning The positioning was completely wrong. First, the coordinates are expressed in ASS playback resolution (which is by default 384x288). Secondly, the coordinates define a drawing rectangle, not a moving area. The previous code was making subtitles move from a random position to another random position. Here we rescale assuming the video resolution is a DVD one (720x480). We can't really do anything better so far, but since this positioning information is often from a DVD rip we can consider them relatively safe. --- libavcodec/srtdec.c | 20 ++++++++++++++++---- tests/ref/fate/sub-srt | 2 +- 2 files changed, 17 insertions(+), 5 deletions(-) diff --git a/libavcodec/srtdec.c b/libavcodec/srtdec.c index a2e62271c8..ed3af95063 100644 --- a/libavcodec/srtdec.c +++ b/libavcodec/srtdec.c @@ -66,10 +66,22 @@ static void srt_to_ass(AVCodecContext *avctx, AVBPrint *dst, strcpy(stack[0].param[PARAM_FACE], "{\\fn}"); if (x1 >= 0 && y1 >= 0) { - if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1)) - av_bprintf(dst, "{\\an1}{\\move(%d,%d,%d,%d)}", x1, y1, x2, y2); - else - av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", x1, y1); + /* XXX: here we rescale coordinate assuming they are in DVD resolution + * (720x480) since we don't have anything better */ + + if (x2 >= 0 && y2 >= 0 && (x2 != x1 || y2 != y1) && x2 >= x1 && y2 >= y1) { + /* text rectangle defined, write the text at the center of the rectangle */ + const int cx = x1 + (x2 - x1)/2; + const int cy = y1 + (y2 - y1)/2; + const int scaled_x = cx * ASS_DEFAULT_PLAYRESX / 720; + const int scaled_y = cy * ASS_DEFAULT_PLAYRESY / 480; + av_bprintf(dst, "{\\an5}{\\pos(%d,%d)}", scaled_x, scaled_y); + } else { + /* only the top left corner, assume the text starts in that corner */ + const int scaled_x = x1 * ASS_DEFAULT_PLAYRESX / 720; + const int scaled_y = y1 * ASS_DEFAULT_PLAYRESY / 480; + av_bprintf(dst, "{\\an1}{\\pos(%d,%d)}", scaled_x, scaled_y); + } } for (; !end && *in; in++) { diff --git a/tests/ref/fate/sub-srt b/tests/ref/fate/sub-srt index 4439857a59..40b20cde90 100644 --- a/tests/ref/fate/sub-srt +++ b/tests/ref/fate/sub-srt @@ -19,7 +19,7 @@ Dialogue: 0,0:00:11.50,0:00:14.50,Default,,0,0,0,,{\b1}This line should be bold{ Dialogue: 0,0:00:14.50,0:00:17.50,Default,,0,0,0,,>\NIt would be a good thing to\Nhide invalid html tags that are closed and show the text in them\Nbut show un-closed invalid html tags\NShow not opened tags\N< Dialogue: 0,0:00:17.50,0:00:20.50,Default,,0,0,0,,and also\Nhide invalid html tags with parameters that are closed and show the text in them\Nbut show un-closed invalid html tags\N{\u1}This text should be showed underlined without problems also: 2<3,5>1,4<6{\u0}\NThis shouldn't be underlined Dialogue: 0,0:00:20.50,0:00:21.50,Default,,0,0,0,,This text should be in the normal position... -Dialogue: 0,0:00:21.50,0:00:22.50,Default,,0,0,0,,{\an1}{\move(0,50,0,100)}This text should NOT be in the normal position +Dialogue: 0,0:00:21.50,0:00:22.50,Default,,0,0,0,,{\an5}{\pos(0,45)}This text should NOT be in the normal position Dialogue: 0,0:00:22.50,0:00:24.50,Default,,0,0,0,,Implementation is the same of the ASS tag\N{\an8}This text should be at the\Ntop and horizontally centered Dialogue: 0,0:00:22.50,0:00:24.50,Default,,0,0,0,,{\an5}This text should be at the\Nmiddle and horizontally centered Dialogue: 0,0:00:22.50,0:00:24.50,Default,,0,0,0,,{\an2}This text should be at the\Nbottom and horizontally centered -- cgit v1.2.3