From 7b382f3acd8a36ed7a889b188f0fc203db76eb4e Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Wed, 19 Jun 2019 19:54:56 +0200
Subject: [PATCH] demux_mkv: add hacks to avoid a single warning

It prints "Unexpected end of file (no clusters found)" when opening a
webm init fragment. The warning is correct, but unwanted in this case.
Add tons of kludges to avoid it.

(Actually it prints that twice, for audio and video each.)

Also, suppress another warning about a seek head entry that points
exactly to the end of the file. This is a MATROSKA_ID_CUES, which is
harmless, and, very strangely, doesn't point at any cues when you
concatenate the init fragment with a media fragment. No idea what that
crap is supposed to be.
---
 demux/demux_mkv.c | 35 ++++++++++++++++++++++++++---------
 1 file changed, 26 insertions(+), 9 deletions(-)

diff --git a/demux/demux_mkv.c b/demux/demux_mkv.c
index c33fab3a2d..65c3559f55 100644
--- a/demux/demux_mkv.c
+++ b/demux/demux_mkv.c
@@ -214,6 +214,8 @@ typedef struct mkv_demuxer {
     // Packets to return.
     struct demux_packet **packets;
     int num_packets;
+
+    bool probably_webm_dash_init;
 } mkv_demuxer_t;
 
 #define OPT_BASE_STRUCT struct demux_mkv_opts
@@ -1945,6 +1947,7 @@ static void probe_x264_garbage(demuxer_t *demuxer)
 
 static int read_ebml_header(demuxer_t *demuxer)
 {
+    mkv_demuxer_t *mkv_d = demuxer->priv;
     stream_t *s = demuxer->stream;
 
     if (ebml_read_id(s) != EBML_ID_EBML)
@@ -1953,15 +1956,22 @@ static int read_ebml_header(demuxer_t *demuxer)
     struct ebml_parse_ctx parse_ctx = { demuxer->log, .no_error_messages = true };
     if (ebml_read_element(s, &parse_ctx, &ebml_master, &ebml_ebml_desc) < 0)
         return 0;
+    bool is_matroska = false, is_webm = false;
     if (!ebml_master.doc_type) {
         MP_VERBOSE(demuxer, "File has EBML header but no doctype. "
                    "Assuming \"matroska\".\n");
-    } else if (strcmp(ebml_master.doc_type, "matroska") != 0
-        && strcmp(ebml_master.doc_type, "webm") != 0) {
+        is_matroska = true;
+    } else if (strcmp(ebml_master.doc_type, "matroska") == 0) {
+        is_matroska = true;
+    } else if (strcmp(ebml_master.doc_type, "webm") == 0) {
+        is_webm = true;
+    }
+    if (!is_matroska && !is_webm) {
         MP_TRACE(demuxer, "no head found\n");
         talloc_free(parse_ctx.talloc_ctx);
         return 0;
     }
+    mkv_d->probably_webm_dash_init &= is_webm;
     if (ebml_master.doc_type_read_version > 2) {
         MP_WARN(demuxer, "This looks like a Matroska file, "
                 "but we don't support format version %"PRIu64"\n",
@@ -2029,6 +2039,15 @@ static int demux_mkv_open(demuxer_t *demuxer, enum demux_check check)
     int64_t start_pos;
     int64_t end_pos;
 
+    mkv_d = talloc_zero(demuxer, struct mkv_demuxer);
+    demuxer->priv = mkv_d;
+    mkv_d->tc_scale = 1000000;
+    mkv_d->a_skip_preroll = 1;
+    mkv_d->skip_to_timecode = INT64_MIN;
+
+    if (demuxer->params)
+        mkv_d->probably_webm_dash_init = demuxer->params->init_fragment.len > 0;
+
     bstr start = stream_peek(s, 4);
     uint32_t start_id = 0;
     for (int n = 0; n < start.len; n++)
@@ -2043,13 +2062,8 @@ static int demux_mkv_open(demuxer_t *demuxer, enum demux_check check)
     if (!read_mkv_segment_header(demuxer, &end_pos))
         return -1;
 
-    mkv_d = talloc_zero(demuxer, struct mkv_demuxer);
-    demuxer->priv = mkv_d;
-    mkv_d->tc_scale = 1000000;
     mkv_d->segment_start = stream_tell(s);
     mkv_d->segment_end = end_pos;
-    mkv_d->a_skip_preroll = 1;
-    mkv_d->skip_to_timecode = INT64_MIN;
 
     mp_read_option_raw(demuxer->global, "index", &m_option_type_choice,
                        &mkv_d->index_mode);
@@ -2065,7 +2079,8 @@ static int demux_mkv_open(demuxer_t *demuxer, enum demux_check check)
         stream_peek(s, 4); // make sure we can always seek back
         uint32_t id = ebml_read_id(s);
         if (s->eof) {
-            MP_WARN(demuxer, "Unexpected end of file (no clusters found)\n");
+            if (!mkv_d->probably_webm_dash_init)
+                MP_WARN(demuxer, "Unexpected end of file (no clusters found)\n");
             break;
         }
         if (id == MATROSKA_ID_CLUSTER) {
@@ -2091,7 +2106,9 @@ static int demux_mkv_open(demuxer_t *demuxer, enum demux_check check)
         // Warn against incomplete files and skip headers outside of range.
         if (elem->pos >= end) {
             elem->parsed = true; // don't bother if file is incomplete
-            if (!mkv_d->eof_warning) {
+            if (!mkv_d->eof_warning && !(mkv_d->probably_webm_dash_init &&
+                                         elem->pos == end))
+            {
                 MP_WARN(demuxer, "SeekHead position beyond "
                         "end of file - incomplete file?\n");
                 mkv_d->eof_warning = true;