add mkv webvtt patch

wang-bin/mdk-sdk#262

patches/master/0034-matroska-support-S_TEXT-WEBVTT.patch

@@ -0,0 +1,108 @@
+From cff3e71ddd009f940385a952bd080456e1fca3f3 Mon Sep 17 00:00:00 2001
+From: wang-bin <wbsecg1@gmail.com>
+Date: Tue, 17 Dec 2024 23:21:57 +0800
+Subject: [PATCH 34/34] matroska: support S_TEXT/WEBVTT
+
+---
+ libavformat/matroska.c    |  1 +
+ libavformat/matroskadec.c | 27 +++++++++++++++++++++++++++
+ 2 files changed, 28 insertions(+)
+
+diff --git a/libavformat/matroska.c b/libavformat/matroska.c
+index d0ecfbeb6a..23c4ad6949 100644
+--- a/libavformat/matroska.c
++++ b/libavformat/matroska.c
+@@ -63,6 +63,7 @@ const CodecTags ff_mkv_codec_tags[]={
+     {"D_WEBVTT/CAPTIONS"    , AV_CODEC_ID_WEBVTT},
+     {"D_WEBVTT/DESCRIPTIONS", AV_CODEC_ID_WEBVTT},
+     {"D_WEBVTT/METADATA"    , AV_CODEC_ID_WEBVTT},
++    {"S_TEXT/WEBVTT"        , AV_CODEC_ID_WEBVTT},
+
+     {"S_TEXT/UTF8"      , AV_CODEC_ID_SUBRIP},
+     {"S_TEXT/UTF8"      , AV_CODEC_ID_TEXT},
+diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
+index 0e150f9138..c0d8e59920 100644
+--- a/libavformat/matroskadec.c
++++ b/libavformat/matroskadec.c
+@@ -3765,6 +3765,7 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
+                                  MatroskaTrack *track,
+                                  AVStream *st,
+                                  uint8_t *data, int data_len,
++                                 MatroskaBlockMore *blockmore, int nb_blockmore,  // style
+                                  uint64_t timecode,
+                                  uint64_t duration,
+                                  int64_t pos)
+@@ -3773,14 +3774,29 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
+     uint8_t *id, *settings, *text, *buf;
+     int id_len, settings_len, text_len;
+     uint8_t *p, *q;
++    int webm_style = !strncmp(track->codec_id, "D_WEBVTT/", 9);
+     int err;
+
+     if (data_len <= 0)
+         return AVERROR_INVALIDDATA;
+
++    if (!webm_style) {
++        text = data;
++        text_len = data_len;
++        if (nb_blockmore <= 0)
++            goto make_pkt;
++        data = blockmore->additional.data;
++        data_len = blockmore->additional.size;
++    }
++
+     p = data;
+     q = data + data_len;
+
++    if (webm_style)
++        goto parse_id;
++    goto parse_settings;
++
++parse_id:
+     id = p;
+     id_len = -1;
+     while (p < q) {
+@@ -3796,7 +3812,11 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
+     if (p >= q || *p != '\n')
+         return AVERROR_INVALIDDATA;
+     p++;
++    if (webm_style)
++        goto parse_text;
++    goto make_pkt;
+
++parse_settings:
+     settings = p;
+     settings_len = -1;
+     while (p < q) {
+@@ -3812,7 +3832,12 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
+     if (p >= q || *p != '\n')
+         return AVERROR_INVALIDDATA;
+     p++;
++    if (webm_style)
++        goto parse_text;
++    goto parse_id;
+
++// parse_comment
++parse_text:
+     text = p;
+     text_len = q - p;
+     while (text_len > 0) {
+@@ -3823,6 +3848,7 @@ static int matroska_parse_webvtt(MatroskaDemuxContext *matroska,
+         text_len = len;
+     }
+
++make_pkt:
+     if (text_len <= 0)
+         return AVERROR_INVALIDDATA;
+
+@@ -4215,6 +4241,7 @@ static int matroska_parse_block(MatroskaDemuxContext *matroska, AVBufferRef *buf
+         } else if (st->codecpar->codec_id == AV_CODEC_ID_WEBVTT) {
+             res = matroska_parse_webvtt(matroska, track, st,
+                                         out_data, out_size,
++                                        blockmore, nb_blockmore,
+                                         timecode, lace_duration,
+                                         pos);
+             if (!buf)
+-- 
+2.39.5 (Apple Git-154)
+