sd_lavc: enable teletext

Whitelisting supported codecs is (probably) still better than just
allowing everything, given the weird FFmpeg API. I'm also assuming
Libav doesn't even have the codec ID, but I didn't check.

Also add a --teletext-page option, since otherwise it decodes every
teletext page and shows them in succession.

And yes, we can't use av_opt_set_int() - instead we have to set it as
string. Because FFmpeg's option system is terrible.

1 files changed, 11 insertions, 0 deletions

diff --git a/sub/sd_lavc.c b/sub/sd_lavc.c
index f310367734..2c1b327b38 100644
--- a/sub/sd_lavc.c
+++ b/sub/sd_lavc.c
@@ -22,6 +22,7 @@
 #include <libavcodec/avcodec.h>
 #include <libavutil/common.h>
 #include <libavutil/intreadwrite.h>
+#include <libavutil/opt.h>
 
 #include "config.h"
 
@@ -106,6 +107,9 @@ static int init(struct sd *sd)
     // Supported codecs must be known to decode to paletted bitmaps
     switch (cid) {
     case AV_CODEC_ID_DVB_SUBTITLE:
+#if LIBAVCODEC_VERSION_MICRO >= 100
+    case AV_CODEC_ID_DVB_TELETEXT:
+#endif
     case AV_CODEC_ID_HDMV_PGS_SUBTITLE:
     case AV_CODEC_ID_XSUB:
     case AV_CODEC_ID_DVD_SUBTITLE:
@@ -339,6 +343,13 @@ static void decode(struct sd *sd, struct demux_packet *packet)
         MP_WARN(sd, "Subtitle with unknown start time.\n");
 
     mp_set_av_packet(&pkt, packet, &priv->pkt_timebase);
+
+    if (ctx->codec_id == AV_CODEC_ID_DVB_TELETEXT) {
+        char page[4];
+        snprintf(page, sizeof(page), "%d", opts->teletext_page);
+        av_opt_set(ctx, "txt_page", page, AV_OPT_SEARCH_CHILDREN);
+    }
+
     int got_sub;
     int res = avcodec_decode_subtitle2(ctx, &sub, &got_sub, &pkt);
     if (res < 0 || !got_sub)