> On Oct 31, 2025, at 03:12, Nicolas George via ffmpeg-devel > <[email protected]> wrote: > > cenzhanquan1 via ffmpeg-devel (HE12025-10-21): >> PR #20731 opened by cenzhanquan1 >> URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20731 >> Patch URL: https://code.ffmpeg.org/FFmpeg/FFmpeg/pulls/20731.patch >> >> The existing avfilter_process_command and avfilter_graph_send_command >> havelimitations in >> command propagation: they only handle commands for individualfilters and >> lack the ability >> to propagate commands through the entire filterchain, nor do they support >> directional >> traversal of the filter graph. Thismakes it difficult to control multiple >> filters in a chain >> (e.g., adjustingvolume for all related filters or enabling/disabling a >> series of filters)with >> a single command. > > You are proposing to add an API without adding any code that uses that > API, let alone user-oriented examples. That makes it impossible to guess > if the feature is useful or if there are better ways to achieve what you > want it to do.
Current implementation isn’t a new API, but new flags. It extends the ways to traverse a graph. The existing API has the capability to send commands to a specific filter, a certain type of filter, or all filters, but it lacks the ability to send commands to a subgraph, unless the user manually filters out all filters belonging to the subgraph, which is possible but complex. The newly added flags provide subgraph traversal capability. A common use case is when a graph contains multiple sources; I want to send commands, such as volume control, to a subgraph with a specific source as the root node, without affecting other sources. While controlling via volume instance names is also feasible, using the source for control offers additional flexibility. > > Regards, > > -- > Nicolas George > _______________________________________________ > ffmpeg-devel mailing list -- [email protected] > To unsubscribe send an email to [email protected] _______________________________________________ ffmpeg-devel mailing list -- [email protected] To unsubscribe send an email to [email protected]
