From f86f213a6d3dd749152a105df839172fe4c772d1 Mon Sep 17 00:00:00 2001 From: Jernej Fijacko Date: Sat, 13 Jul 2019 19:33:16 +0200 Subject: [PATCH] avcodec/dvbsub: add support for Display Definition Segment to DVB Subtitle encoder Current version of dvbsub encoder doesn't support HD DVB subtitles. The high resolution bitmaps are muxed into the stream but without the DDS (display definition segment) the players asume that the DVB subtitles are in SD (720x576) resolution which causes them to either render the subtitles too large and misplaced or don't render them at all. By including the DDS as defined in section 7.7.1 of ETSI EN 300 743 (V1.3.1) this problem is fixed. 7.2.1 Display definition segment The display definition for a subtitle service may be defined by the display definition segment if present in the stream. Absence of a DDS implies that the stream is coded in accordance with EN 300 743 (V1.2.1) [5] and that a display width of 720 pixels and a display height of 576 lines may be assumed. https://www.etsi.org/deliver/etsi_en/300700_300799/300743/01.03.01_60/en_300743v010301p.pdf Signed-off-by: Jernej Fijacko Signed-off-by: Marton Balint --- libavcodec/dvbsub.c | 19 ++++++++++++++++--- 1 file changed, 16 insertions(+), 3 deletions(-) diff --git a/libavcodec/dvbsub.c b/libavcodec/dvbsub.c index 8cce702a9e..a8d43d81d6 100644 --- a/libavcodec/dvbsub.c +++ b/libavcodec/dvbsub.c @@ -247,9 +247,10 @@ static void dvb_encode_rle8(uint8_t **pq, *pq = q; } -static int encode_dvb_subtitles(DVBSubtitleContext *s, +static int encode_dvb_subtitles(AVCodecContext *avctx, uint8_t *outbuf, const AVSubtitle *h) { + DVBSubtitleContext *s = avctx->priv_data; uint8_t *q, *pseg_len; int page_id, region_id, clut_id, object_id, i, bpp_index, page_state; @@ -261,6 +262,19 @@ static int encode_dvb_subtitles(DVBSubtitleContext *s, if (h->num_rects && !h->rects) return -1; + if (avctx->width > 0 && avctx->height > 0) { + /* display definition segment */ + *q++ = 0x0f; /* sync_byte */ + *q++ = 0x14; /* segment_type */ + bytestream_put_be16(&q, page_id); + pseg_len = q; + q += 2; /* segment length */ + *q++ = 0x00; /* dds version number & display window flag */ + bytestream_put_be16(&q, avctx->width - 1); /* display width */ + bytestream_put_be16(&q, avctx->height - 1); /* display height */ + bytestream_put_be16(&pseg_len, q - pseg_len - 2); + } + /* page composition segment */ *q++ = 0x0f; /* sync_byte */ @@ -446,10 +460,9 @@ static int dvbsub_encode(AVCodecContext *avctx, unsigned char *buf, int buf_size, const AVSubtitle *sub) { - DVBSubtitleContext *s = avctx->priv_data; int ret; - ret = encode_dvb_subtitles(s, buf, sub); + ret = encode_dvb_subtitles(avctx, buf, sub); return ret; }