From f103731e21e14efbc5efea32f1504eb99f45b10e Mon Sep 17 00:00:00 2001 From: Nicolas George Date: Fri, 14 Aug 2020 11:21:39 +0200 Subject: [PATCH] lavfi/buffersink: add a summary documentation of the API. --- libavfilter/buffersink.h | 36 ++++++++++++++++++++++++++++++++++++ 1 file changed, 36 insertions(+) diff --git a/libavfilter/buffersink.h b/libavfilter/buffersink.h index c0e6b5386f..65d0cca747 100644 --- a/libavfilter/buffersink.h +++ b/libavfilter/buffersink.h @@ -31,6 +31,42 @@ * @defgroup lavfi_buffersink Buffer sink API * @ingroup lavfi * @{ + * + * The buffersink and abuffersink filters are there to connect filter graphs + * to applications. They have a single input, connected to the graph, and no + * output. Frames must be extracted using av_buffersink_get_frame() or + * av_buffersink_get_samples(). + * + * The format negotiated by the graph during configuration can be obtained + * using the accessor functions: + * - av_buffersink_get_time_base(), + * - av_buffersink_get_format(), + * - av_buffersink_get_frame_rate(), + * - av_buffersink_get_w(), + * - av_buffersink_get_h(), + * - av_buffersink_get_sample_aspect_ratio(), + * - av_buffersink_get_channels(), + * - av_buffersink_get_channel_layout(), + * - av_buffersink_get_sample_rate(). + * + * The format can be constrained by setting options, using av_opt_set() and + * related functions with the AV_OPT_SEARCH_CHILDREN flag. + * - pix_fmts (int list), + * - sample_fmts (int list), + * - sample_rates (int list), + * - channel_layouts (int64_t), + * - channel_counts (int list), + * - all_channel_counts (bool). + * Most of these options are of type binary, and should be set using + * av_opt_set_int_list() or av_opt_set_bin(). If they are not set, all + * corresponding formats are accepted. + * + * As a special case, if neither channel_layouts nor channel_counts is set, + * all valid channel layouts are accepted, but channel counts without a + * layout are not, unless all_channel_counts is set. + * Also, channel_layouts must not contain a channel layout already accepted + * by a value in channel_counts; for example, if channel_counts contains 2, + * then channel_layouts must not contain stereo. */ /**