Various subtitle fixes.

1 files changed, 31 insertions, 24 deletions

diff --git a/src/lib/ffmpeg_decoder.cc b/src/lib/ffmpeg_decoder.cc
index cf17bbfb7..808e5ac9b 100644
--- a/src/lib/ffmpeg_decoder.cc
+++ b/src/lib/ffmpeg_decoder.cc
@@ -27,6 +27,7 @@
 #include <iomanip>
 #include <iostream>
 #include <stdint.h>
+#include <boost/lexical_cast.hpp>
 extern "C" {
 #include <tiffio.h>
 #include <libavcodec/avcodec.h>
@@ -231,7 +232,6 @@ FFmpegDecoder::do_pass ()
 
 		int frame_finished;
 		if (avcodec_decode_video2 (_video_codec_context, _frame, &frame_finished, &_packet) >= 0 && frame_finished) {
-			maybe_add_subtitle ();
 			process_video (_frame);
 		}
 
@@ -355,7 +355,7 @@ FFmpegDecoder::sample_aspect_ratio_denominator () const
 }
 
 void
-FFmpegDecoder::maybe_add_subtitle ()
+FFmpegDecoder::overlay (shared_ptr<Image> image) const
 {
 	if (!_have_subtitle) {
 		return;
@@ -368,32 +368,34 @@ FFmpegDecoder::maybe_add_subtitle ()
 	float const to = packet_time + (float (_subtitle.end_display_time) / 1e3);
 	
 	float const video_frame_time = float (last_video_frame ()) / rint (_fs->frames_per_second);
-	
-	if (from < video_frame_time || video_frame_time > to) {
+
+	if (from > video_frame_time || video_frame_time < to) {
 		return;
 	}
-	
+
 	for (unsigned int i = 0; i < _subtitle.num_rects; ++i) {
 		AVSubtitleRect* rect = _subtitle.rects[i];
 		if (rect->type != SUBTITLE_BITMAP) {
 			throw DecodeError ("non-bitmap subtitles not yet supported");
 		}
-		
-		/* XXX: all this assumes YUV420 in _frame */
+
+		/* XXX: all this assumes YUV420 in image */
 		
 		assert (rect->pict.data[0]);
 
-		/* Start of the first line in the target frame */
-		uint8_t* frame_y_p = _frame->data[0] + rect->y * _frame->linesize[0];
-		uint8_t* frame_u_p = _frame->data[1] + (rect->y / 2) * _frame->linesize[1];
-		uint8_t* frame_v_p = _frame->data[2] + (rect->y / 2) * _frame->linesize[2];
+		/* Start of the first line in the target image */
+		uint8_t* frame_y_p = image->data()[0] + rect->y * image->line_size()[0];
+		uint8_t* frame_u_p = image->data()[1] + (rect->y / 2) * image->line_size()[1];
+		uint8_t* frame_v_p = image->data()[2] + (rect->y / 2) * image->line_size()[2];
+
+		int const hlim = min (rect->y + rect->h, image->size().height) - rect->y;
 		
 		/* Start of the first line in the subtitle */
 		uint8_t* sub_p = rect->pict.data[0];
 		/* sub_p looks up into a RGB palette which is here */
 		uint32_t const * palette = (uint32_t *) rect->pict.data[1];
 		
-		for (int sub_y = 0; sub_y < rect->h; ++sub_y) {
+		for (int sub_y = 0; sub_y < hlim; ++sub_y) {
 			/* Pointers to the start of this line */
 			uint8_t* sub_line_p = sub_p;
 			uint8_t* frame_line_y_p = frame_y_p + rect->x;
@@ -401,8 +403,8 @@ FFmpegDecoder::maybe_add_subtitle ()
 			uint8_t* frame_line_v_p = frame_v_p + (rect->x / 2);
 			
 			/* U and V are subsampled */
-			uint8_t current_u = 0;
-			uint8_t current_v = 0;
+			uint8_t next_u = 0;
+			uint8_t next_v = 0;
 			int subsample_step = 0;
 			
 			for (int sub_x = 0; sub_x < rect->w; ++sub_x) {
@@ -420,29 +422,34 @@ FFmpegDecoder::maybe_add_subtitle ()
 				*frame_line_y_p++ = int (cy * (1 - alpha)) + int (RGB_TO_Y_CCIR (red, green, blue) * alpha);
 				
 				/* Store up U and V */
-				current_u |= ((RGB_TO_U_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step);
-				current_v |= ((RGB_TO_V_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step);
+				next_u |= ((RGB_TO_U_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step);
+				next_v |= ((RGB_TO_V_CCIR (red, green, blue, 0) & 0xf0) >> 4) << (4 * subsample_step);
 				
 				if (subsample_step == 1 && (sub_y % 2) == 0) {
-					/* We have complete U and V bytes, so alpha-blend them into the frame */
 					int const cu = *frame_line_u_p;
 					int const cv = *frame_line_v_p;
-					*frame_line_u_p++ = int (cu * (1 - alpha)) + int (current_u * alpha);
-					*frame_line_v_p++ = int (cv * (1 - alpha)) + int (current_v * alpha);
-					current_u = current_v = 0;
+
+					*frame_line_u_p++ =
+						int (((cu & 0x0f) * (1 - alpha) + (next_u & 0x0f) * alpha)) |
+						int (((cu & 0xf0) * (1 - alpha) + (next_u & 0xf0) * alpha));
+
+					*frame_line_v_p++ = 
+						int (((cv & 0x0f) * (1 - alpha) + (next_v & 0x0f) * alpha)) |
+						int (((cv & 0xf0) * (1 - alpha) + (next_v & 0xf0) * alpha));
+					
+					next_u = next_v = 0;
 				}
 				
 				subsample_step = (subsample_step + 1) % 2;
 			}
 			
 			sub_p += rect->pict.linesize[0];
-			frame_y_p += _frame->linesize[0];
+			frame_y_p += image->line_size()[0];
 			if ((sub_y % 2) == 0) {
-				frame_u_p += _frame->linesize[1];
-				frame_v_p += _frame->linesize[2];
+				frame_u_p += image->line_size()[1];
+				frame_v_p += image->line_size()[2];
 			}
 		}
 	}
 }
-