[FFmpeg-devel] [PATCH 1/2] lavc/bsf: add general documentation

[James Almer]

On 2/22/2022 3:27 AM, Anton Khirnov wrote:
> Also, place the BSF api docs in their own doxygen group.
> ---
>   libavcodec/bsf.h | 23 ++++++++++++++++++++++-
>   1 file changed, 22 insertions(+), 1 deletion(-)
> 
> diff --git a/libavcodec/bsf.h b/libavcodec/bsf.h
> index 8c5355d186..ba8b48f222 100644
> --- a/libavcodec/bsf.h
> +++ b/libavcodec/bsf.h
> @@ -30,7 +30,28 @@
>   #include "packet.h"
>   
>   /**
> - * @addtogroup lavc_core
> + * @defgroup lavc_bsf Bitstream filters
> + * @ingroup libavc
> + *
> + * Bitstream filters transform encoded media data without decoding it. This
> + * allows e.g. manipulating various header values. Bitstream filters operate on
> + * @ref AVPacket "AVPackets".
> + *
> + * The bitstream filtering API is centered around two structures:
> + * AVBitStreamFilter and AVBSFContext. The former represents a bitstream filter

Could use @ref here and below, too.

> + * in abstract, the latter a specific filtering process. Obtain an
> + * AVBitStreamFilter using av_bsf_get_by_name() or av_bsf_iterate(), then pass
> + * it to av_bsf_alloc() to create an AVBSFContext. Fill in the user-settable
> + * AVBSFContext fields, as described in its documentation, then call
> + * av_bsf_init() to prepare the filter context for use.
> + *
> + * Submit packets for filtering using av_bsf_send_packet(), obtain filtered
> + * results with av_bsf_receive_packet(). When no more input packets will be
> + * sent, submit a NULL AVPacket to signal the end of the stream to the filter.

The doxy for av_bsf_send_packet() states the packet must be "empty", 
meaning either "NULL, or pkt->data is NULL and pkt->side_data_elems 
zero", so probably mention the same here so it's consistent.

> + * av_bsf_receive_packet() will then return trailing packets, if any are
> + * produced by the filter.
> + *
> + * Finally, free the filter context with av_bsf_free().
>    * @{
>    */

LGTM otherwise.