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.
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
> Content-Type: multipart/mixed; boundary="------------1.8.3.1"
>
> This is a multi-part message in MIME format.
> --------------1.8.3.1
> Content-Type: text/plain; charset=UTF-8; format=fixed
> Content-Transfer-Encoding: 8bit
>
> ---
> doc/muxers.texi | 3 ++-
> libavformat/tee.c | 32 +++++++++++++++++++++++---------
> 2 files changed, 25 insertions(+), 10 deletions(-)
>
>
> --------------1.8.3.1
> Content-Type: text/x-patch;
> name="0001-select-attribute-of-tee-pseudo-demuxer-may-contain-m.patch"
> Content-Transfer-Encoding: 8bit
> Content-Disposition: attachment;
> 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.
>
> 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.
> +
> + 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,
--
Nicolas George
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