See my interleaved comments below.
2015.10.04. 18:50 keltezéssel, Nicolas George írta:
Le decadi 10 vendémiaire, an CCXXIV, Bodecs Bela a écrit :
thank you for your feedback, I have altered the patch accordingly. I have
enclosed the updated patch file.
Please remember not to top-post on these mailing-lists.
I am very sorry. I won't do it again.
See interleaved comments below.
From bcbd5e3e1a850fef1002d3a63c06fc52b2a3d169 Mon Sep 17 00:00:00 2001
From: Bela Bodecs <bode...@vivanet.hu>
Date: Thu, 1 Oct 2015 13:00:50 +0200
Subject: [PATCH 1/1] select attribute of tee pseudo demuxer may contain
multiple stream specifiers
MIME-Version: 1.0
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--------------1.8.3.1
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---
doc/muxers.texi | 3 ++-
libavformat/tee.c | 32 +++++++++++++++++++++++---------
2 files changed, 25 insertions(+), 10 deletions(-)
--------------1.8.3.1
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name="0001-select-attribute-of-tee-pseudo-demuxer-may-contain-m.patch"
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filename="0001-select-attribute-of-tee-pseudo-demuxer-may-contain-m.patch"
This is rather strange. I wonder how you managed to produce this patch.
git add libavformat/tee.c
git add doc/muxers.texi
git commit -m "select attribute of tee pseudo demuxer may contain
multiple stream specifiers"
git format-patch -n -o /tmp/ --attach origin
diff --git a/doc/muxers.texi b/doc/muxers.texi
index d75d7de..113b76a 100644
--- a/doc/muxers.texi
+++ b/doc/muxers.texi
@@ -1224,7 +1224,8 @@ Several bitstream filters can be specified, separated by
",".
@item select
Select the streams that should be mapped to the slave output,
specified by a stream specifier. If not specified, this defaults to
-all the input streams.
+all the input streams. You may use multiple stream specifiers
+separated by commas (@code{,}) e.g.: @code{a:0,v}
@end table
@subsection Examples
diff --git a/libavformat/tee.c b/libavformat/tee.c
index e3d466a..7d67652 100644
--- a/libavformat/tee.c
+++ b/libavformat/tee.c
@@ -47,6 +47,7 @@ static const char *const slave_opt_open = "[";
static const char *const slave_opt_close = "]";
static const char *const slave_opt_delim = ":]"; /* must have the close too */
static const char *const slave_bsfs_spec_sep = "/";
+static const char *const slave_select_sep = ",";
static const AVClass tee_muxer_class = {
.class_name = "Tee muxer",
@@ -142,7 +143,9 @@ static int open_slave(AVFormatContext *avf, char *slave,
TeeSlave *tee_slave)
AVFormatContext *avf2 = NULL;
AVStream *st, *st2;
int stream_count;
-
+ int fullret;
+ char *subselect = NULL, *next_subselect = NULL, *first_subselect;
+
if ((ret = parse_slave_options(avf, slave, &options, &filename)) < 0)
return ret;
@@ -172,15 +175,26 @@ static int open_slave(AVFormatContext *avf, char *slave, TeeSlave *tee_slave)
for (i = 0; i < avf->nb_streams; i++) {
st = avf->streams[i];
if (select) {
- ret = avformat_match_stream_specifier(avf, avf->streams[i],
select);
- if (ret < 0) {
- av_log(avf, AV_LOG_ERROR,
- "Invalid stream specifier '%s' for output '%s'\n",
- select, slave);
- goto end;
- }
+ fullret = 0;
+ first_subselect = select;
+ next_subselect = NULL;
+ while (subselect = av_strtok(first_subselect, slave_select_sep,
&next_subselect)) {
+ first_subselect = NULL;
I was about to say "LGTM", but I just noticed this: av_strtok(), just like
strtok(), is destructive: it replace the delimiters by a NUL character in
the original string. If it is called again with the same string, it will
only see the first token.
Unless I am mistaken, this is what will happen here: if the specifier is
"0,1", the stream #0 will be matched on the first round of the loop, but
then stream #1 will only see select as "0", no longer "0,1".
Fixing it can be done easily enough, though. For example with av_strdup() on
the string (but beware of the leaks).
I am a bit surprised you did not catch this during testing. Maybe I am
missing something.
You would be right unless I used
first_subselect = NULL;
right after the while statement, so the next round av_strtok will go
further, because the first parameter will be null, not the same string
and next_subselect will point the next start.
Yes it is destructive, but we never use this string (select) again in
this function.
I swear, I have really tested it, I use it on my own in my production
environment.
+
+ ret = avformat_match_stream_specifier(avf, avf->streams[i],
subselect);
+ if (ret < 0) {
+ av_log(avf, AV_LOG_ERROR,
+ "Invalid stream specifier '%s' for output '%s'\n",
+ subselect, slave);
+ goto end;
+ }
+ if (ret != 0) {
+ fullret = 1; // match
+ break;
+ }
- if (ret == 0) { /* no match */
+ }
+ if (fullret == 0) { /* no match */
tee_slave->stream_map[i] = -1;
continue;
}
Regards,
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best regards,
Bela Bodecs
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