From 061a0c14bb5767bca72e3a7227ca400de439ba09 Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Wed, 26 Oct 2016 13:59:15 +0200 Subject: decode: restructure the core decoding code Currently, the new decoding API is pretty much just a wrapper around the old deprecated one. This is problematic, since it interferes with making full use of the flexibility added by the new API. The old API should also be removed at some future point. Reorganize the code so that the new send_packet/receive_frame functions call the actual decoding directly and change the old deprecated avcodec_decode_* functions into wrappers around the new API. The new internal API for decoders is now changing as well. Before this commit, it mirrors the public API, so the decoders need to implement send_packet() and receive_frame() callbacks. This turns out to require awkward constructs in both the decoders and the generic code. After this commit, the decoders only implement the receive_frame() callback and call a new internal function, ff_decode_get_packet() to obtain input data, in the same manner to how the bitstream filters now work. avcodec will now always make a reference to the input packet, which means that non-refcounted input packets will be copied. Keeping the previous behaviour, where this copy could sometimes be avoided, would make the code significantly more complex and fragile for only dubious gains, since packets are typically small and everyone who cares about performance should use refcounted packets anyway. --- libavcodec/decode.h | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 libavcodec/decode.h (limited to 'libavcodec/decode.h') diff --git a/libavcodec/decode.h b/libavcodec/decode.h new file mode 100644 index 0000000000..21c7c3e07a --- /dev/null +++ b/libavcodec/decode.h @@ -0,0 +1,35 @@ +/* + * generic decoding-related code + * + * This file is part of Libav. + * + * Libav is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * Libav is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with Libav; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_DECODE_H +#define AVCODEC_DECODE_H + +/** + * Called by decoders to get the next packet for decoding. + * + * @param pkt An empty packet to be filled with data. + * @return 0 if a new reference has been successfully written to pkt + * AVERROR(EAGAIN) if no data is currently available + * AVERROR_EOF if and end of stream has been reached, so no more data + * will be available + */ +int ff_decode_get_packet(AVCodecContext *avctx, AVPacket *pkt); + +#endif /* AVCODEC_DECODE_H */ -- cgit v1.2.3