Avoids allocations and therefore error checks; also avoids indirections and allows to remove the boilerplate code for creating an object with a dedicated free function. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
		
			
				
	
	
		
			132 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			132 lines
		
	
	
		
			3.8 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * V4L2 mem2mem helper functions
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 *
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 * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org>
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 * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVCODEC_V4L2_M2M_H
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#define AVCODEC_V4L2_M2M_H
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#include <semaphore.h>
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#include <unistd.h>
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#include <dirent.h>
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#include <linux/videodev2.h>
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#include "libavcodec/avcodec.h"
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#include "v4l2_context.h"
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#define container_of(ptr, type, member) ({ \
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        const __typeof__(((type *)0)->member ) *__mptr = (ptr); \
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        (type *)((char *)__mptr - offsetof(type,member) );})
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#define V4L_M2M_DEFAULT_OPTS \
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    { "num_output_buffers", "Number of buffers in the output context",\
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        OFFSET(num_output_buffers), AV_OPT_TYPE_INT, { .i64 = 16 }, 2, INT_MAX, FLAGS }
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typedef struct V4L2m2mContext {
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    char devname[PATH_MAX];
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    int fd;
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    /* the codec context queues */
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    V4L2Context capture;
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    V4L2Context output;
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    /* dynamic stream reconfig */
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    AVCodecContext *avctx;
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    sem_t refsync;
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    atomic_uint refcount;
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    int reinit;
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    /* null frame/packet received */
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    int draining;
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    AVPacket buf_pkt;
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    /* Reference to a frame. Only used during encoding */
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    AVFrame *frame;
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    /* Reference to self; only valid while codec is active. */
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    struct V4L2m2mContext *self_ref;
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    /* reference back to V4L2m2mPriv */
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    void *priv;
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} V4L2m2mContext;
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typedef struct V4L2m2mPriv {
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    AVClass *class;
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    V4L2m2mContext *context;   ///< RefStruct reference
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    int num_output_buffers;
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    int num_capture_buffers;
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} V4L2m2mPriv;
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/**
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 * Allocate a new context and references for a V4L2 M2M instance.
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 *
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 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder.
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 * @param[out] ctx The V4L2m2mContext.
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 *
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 * @returns 0 in success, a negative error code otherwise.
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 */
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int ff_v4l2_m2m_create_context(V4L2m2mPriv *priv, V4L2m2mContext **s);
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/**
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 * Probes the video nodes looking for the required codec capabilities.
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 *
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 * @param[in] ctx The V4L2m2mPriv instantiated by the encoder/decoder.
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 *
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 * @returns 0 if a driver is found, a negative number otherwise.
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 */
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int ff_v4l2_m2m_codec_init(V4L2m2mPriv *priv);
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/**
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 * Releases all the codec resources if all AVBufferRefs have been returned to the
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 * ctx. Otherwise keep the driver open.
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 *
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 * @param[in] The V4L2m2mPriv instantiated by the encoder/decoder.
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 *
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 * @returns 0
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 *
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 */
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int ff_v4l2_m2m_codec_end(V4L2m2mPriv *priv);
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/**
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 * Reinitializes the V4L2m2mContext when the driver cannot continue processing
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 * with the capture parameters.
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 *
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 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
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 *
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 * @returns 0 in case of success, negative number otherwise
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 */
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int ff_v4l2_m2m_codec_reinit(V4L2m2mContext *ctx);
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/**
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 * Reinitializes the V4L2m2mContext when the driver cannot continue processing
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 * with the  any of the current V4L2Contexts (ie, changes in output and capture).
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 *
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 * @param[in] ctx The V4L2m2mContext instantiated by the encoder/decoder.
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 *
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 * @returns 0 in case of success, negative number otherwise
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 */
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int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *ctx);
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#endif /* AVCODEC_V4L2_M2M_H */
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