[FFmpeg-devel] [PATCH v2] ffmpeg: add per-stream input option drop_changed

[Gyan Doshi]

On 2025-03-16 11:12 pm, James Almer wrote:
> On 3/16/2025 4:18 AM, Gyan Doshi wrote:
>> This is a replacement in ffmpeg for the deprecated avcodec flag 
>> AV_CODEC_FLAG_DROPCHANGED.
>>
>> This option is meant to be used when the filtergraph should not be
>> reinited upon input parameter changes as that leads to loss of state
>> in the filtergraph potentially leading to broken or aborted output,
>> e.g. inserting of silence with first_pts specified in aresample.
>>
>> Generally useful to avoid corrupted yet decodable packets in live
>> streaming inputs.
>>
>> This option when enabled takes precedence over reinit_filters
>
> How does this differ from simply setting reinit_filter to false, if 
> what you want is the filtergraph to not be reinitialized?

av_buffersrc_add_frame_flags will return an error for all audio frames 
with differing parameters, as no filters are yet capable of handling 
them. ultimately leading to program exit.
Same is true for video frames barring a handful of filters like scale or 
idet ..etc

Regards,
Gyan