[FFmpeg-devel] [PATCH v3] avformat/concatdec: add support for setting input options
Nicolas George
george at nsup.org
Wed Feb 10 20:32:59 EET 2021
Jan Ekström (12021-02-08):
> This way protocol or format related options can be set for all
> of the files opened during concatenation both globally as well
> as per-file.
> ---
>
> Changes from v2:
>
> 1. Added an example, although I had issues figuring out something useful
> that is not a hack for something. Ended up doing a disablement of
> advanced edit list functionality, since that can sometimes lead to
> unwanted behavior.
>
> * First idea was to override the input format for a file without an
> extension. For that, we have no AVOption it seems.
Indeed, lavf does not accept it as an option. It needs to be added
separately. Or we can make it an option.
> * Then came the idea of utilizing the framerate option in the raw
> h264 demuxer. That didn't work because apparently if there is a header
> in there that probed/parsed frame rate field gets utilized.
You could set the frame rate for a raw video stream.
> * Third idea was either the one I picked, or analyzeduration/probesize
> for MPEG-TS. I opted for the mp4 case.
>
> 2. Quoted the : in documentation with @code{:}.
> 3. Fixed a duplicate space in a log message.
> ---
>
> doc/demuxers.texi | 24 ++++++++++++++
> libavformat/concatdec.c | 69 ++++++++++++++++++++++++++++++++++++++++-
> 2 files changed, 92 insertions(+), 1 deletion(-)
>
> diff --git a/doc/demuxers.texi b/doc/demuxers.texi
> index 3c15ab9eee..20601f9575 100644
> --- a/doc/demuxers.texi
> +++ b/doc/demuxers.texi
> @@ -149,6 +149,14 @@ Metadata of the packets of the file. The specified metadata will be set for
> each file packet. You can specify this directive multiple times to add multiple
> metadata entries.
>
> + at item @code{input_options @var{key=value:key2=value2}}
> +Input options passed on when reading a specific file, using a @code{:}-separated
> +list of key=value pairs.
No! Why would you do that? It adds one level of escaping, we already
have way too much of them.
input option key=value
singular, and can be set as many times as necessary.
> Requires @code{safe} to be non-positive.
Zero would be safer.
> Global options
> +for all files can be set with the @code{input_options} demuxer option. When using
> +both options on the list of files as well as globally via the demuxer option,
> +the global ones get applied first and the file-specific options are then applied
> +on top of them.
I am not sure it is the right order. Options added on the fly should
take precedence over options written in a file, in general. But the
global / specific distinction makes it less clear-cut.
Other opinions?
> +
> @item @code{stream}
> Introduce a stream in the virtual file.
> All subsequent stream-related directives apply to the last introduced
> @@ -204,6 +212,10 @@ expressed in microseconds. The duration metadata is only set if it is known
> based on the concat file.
> The default is 0.
>
> + at item input_options
> +Input options to be passed on for all opened inputs using
> a :-separated list of
It should say "a dictionary", with a link to where the syntax of
dictionaries is documented, but whoever added AV_OPT_TYPE_DICT neglected
to add the corresponding documentation paragraph :(
> +key=value pairs.
> +
> @end table
>
> @subsection Examples
> @@ -231,6 +243,18 @@ duration 20.0
>
> file subdir/file-2.wav
> @end example
> +
> + at item
> +Disabling advanced edit list capability for the first input file via
> +input_options:
> + at example
> +ffconcat version 1.0
> +
> +file file-1.mp4
> +input_options advanced_editlist=false
> +
> +file file-2.mp4
> + at end example
> @end itemize
>
> @section dash
> diff --git a/libavformat/concatdec.c b/libavformat/concatdec.c
> index 6d5b9914f9..89d75cedc6 100644
> --- a/libavformat/concatdec.c
> +++ b/libavformat/concatdec.c
> @@ -52,6 +52,7 @@ typedef struct {
> int64_t outpoint;
> AVDictionary *metadata;
> int nb_streams;
> + AVDictionary *input_options;
> } ConcatFile;
>
> typedef struct {
> @@ -66,6 +67,7 @@ typedef struct {
> ConcatMatchMode stream_match_mode;
> unsigned auto_convert;
> int segment_time_metadata;
> + AVDictionary *input_options;
> } ConcatContext;
>
> static int concat_probe(const AVProbeData *probe)
> @@ -329,6 +331,7 @@ static int open_file(AVFormatContext *avf, unsigned fileno)
> {
> ConcatContext *cat = avf->priv_data;
> ConcatFile *file = &cat->files[fileno];
> + AVDictionary *options = NULL;
> int ret;
>
> if (cat->avf)
> @@ -344,12 +347,37 @@ static int open_file(AVFormatContext *avf, unsigned fileno)
> if ((ret = ff_copy_whiteblacklists(cat->avf, avf)) < 0)
> return ret;
>
> - if ((ret = avformat_open_input(&cat->avf, file->url, NULL, NULL)) < 0 ||
> + // Apply global AVOptions first
> + if (cat->input_options &&
> + (ret = av_dict_copy(&options, cat->input_options, 0) < 0))
> + return ret;
> +
> + // then apply file-specific AVOptions
> + if (file->input_options &&
> + (ret = av_dict_copy(&options, file->input_options, 0) < 0))
> + return ret;
> +
> + if ((ret = avformat_open_input(&cat->avf, file->url, NULL, &options)) < 0 ||
> (ret = avformat_find_stream_info(cat->avf, NULL)) < 0) {
> av_log(avf, AV_LOG_ERROR, "Impossible to open '%s'\n", file->url);
> avformat_close_input(&cat->avf);
> + av_dict_free(&options);
> return ret;
> }
> +
> + if (av_dict_count(options)) {
> + AVDictionaryEntry *en = NULL;
> +
> + while ((en = av_dict_get(options, "", en, AV_DICT_IGNORE_SUFFIX))) {
> + av_log(avf, AV_LOG_WARNING,
> + "Option '%s' set to '%s' was ignored when opening %s "
> + "with the %s reader!\n",
> + en->key, en->value, file->url, cat->avf->iformat->name);
> + }
> + }
> +
> + av_dict_free(&options);
> +
> cat->cur_file = file;
> file->start_time = !fileno ? 0 :
> cat->files[fileno - 1].start_time +
> @@ -386,6 +414,7 @@ static int concat_read_close(AVFormatContext *avf)
> }
> av_freep(&cat->files[i].streams);
> av_dict_free(&cat->files[i].metadata);
> + av_dict_free(&cat->files[i].input_options);
> }
> if (cat->avf)
> avformat_close_input(&cat->avf);
> @@ -457,6 +486,41 @@ static int concat_read_header(AVFormatContext *avf)
> FAIL(AVERROR_INVALIDDATA);
> }
> av_freep(&metadata);
> + } else if (!strncmp(keyword, "input_options", 13)) {
> + if (!file) {
> + av_log(avf, AV_LOG_ERROR, "Line %d: %s without file\n",
> + line, keyword);
> + FAIL(AVERROR_INVALIDDATA);
> + }
> +
> + if (cat->safe > 0) {
> + av_log(avf, AV_LOG_ERROR,
> + "Line %d: Input options cannot be set in file list in "
> + "safe mode!\n", line);
> + FAIL(AVERROR(EPERM));
> + }
> +
> + {
> + char *input_options = av_get_token((const char **)&cursor,
> + SPACE_CHARS);
> + if (!input_options) {
> + av_log(avf, AV_LOG_ERROR,
> + "Line %d: key=value pairs required!\n", line);
> + FAIL(AVERROR_INVALIDDATA);
> + }
> +
> + if ((ret =
> + av_dict_parse_string(&file->input_options, input_options,
> + "=", ":", 0)) < 0) {
Just find the first = and add a single key-value.
> + av_log(avf, AV_LOG_ERROR,
> + "Line %d: failed to parse input options string\n",
> + line);
> + av_freep(&input_options);
> + FAIL(AVERROR_INVALIDDATA);
> + }
> +
> + av_freep(&input_options);
> + }
> } else if (!strcmp(keyword, "stream")) {
> if (!avformat_new_stream(avf, NULL))
> FAIL(AVERROR(ENOMEM));
> @@ -764,6 +828,9 @@ static const AVOption options[] = {
> OFFSET(auto_convert), AV_OPT_TYPE_BOOL, {.i64 = 1}, 0, 1, DEC },
> { "segment_time_metadata", "output file segment start time and duration as packet metadata",
> OFFSET(segment_time_metadata), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
> + { "input_options",
> + "set options for all opened inputs using a :-separated list of key=value pairs",
> + OFFSET(input_options), AV_OPT_TYPE_DICT, { .str = NULL }, 0, 0, DEC },
> { NULL }
> };
>
Regards,
--
Nicolas George
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