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Diffstat (limited to 'libavcodec/v4l2_buffers.h')
-rw-r--r-- | libavcodec/v4l2_buffers.h | 131 |
1 files changed, 131 insertions, 0 deletions
diff --git a/libavcodec/v4l2_buffers.h b/libavcodec/v4l2_buffers.h new file mode 100644 index 0000000..dc5cc9e --- /dev/null +++ b/libavcodec/v4l2_buffers.h @@ -0,0 +1,131 @@ +/* + * V4L2 buffer helper functions. + * + * Copyright (C) 2017 Alexis Ballier <aballier@gentoo.org> + * Copyright (C) 2017 Jorge Ramirez <jorge.ramirez-ortiz@linaro.org> + * + * This file is part of FFmpeg. + * + * FFmpeg 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. + * + * FFmpeg 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 FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#ifndef AVCODEC_V4L2_BUFFERS_H +#define AVCODEC_V4L2_BUFFERS_H + +#include <stdatomic.h> +#include <linux/videodev2.h> + +#include "avcodec.h" + +enum V4L2Buffer_status { + V4L2BUF_AVAILABLE, + V4L2BUF_IN_DRIVER, + V4L2BUF_RET_USER, +}; + +/** + * V4L2Buffer (wrapper for v4l2_buffer management) + */ +typedef struct V4L2Buffer { + /* each buffer needs to have a reference to its context */ + struct V4L2Context *context; + + /* This object is refcounted per-plane, so we need to keep track + * of how many context-refs we are holding. */ + AVBufferRef *context_ref; + atomic_uint context_refcount; + + /* keep track of the mmap address and mmap length */ + struct V4L2Plane_info { + int bytesperline; + void * mm_addr; + size_t length; + } plane_info[VIDEO_MAX_PLANES]; + + int num_planes; + + /* the v4l2_buffer buf.m.planes pointer uses the planes[] mem */ + struct v4l2_buffer buf; + struct v4l2_plane planes[VIDEO_MAX_PLANES]; + + int flags; + enum V4L2Buffer_status status; + +} V4L2Buffer; + +/** + * Extracts the data from a V4L2Buffer to an AVFrame + * + * @param[in] frame The AVFRame to push the information to + * @param[in] buf The V4L2Buffer to get the information from + * + * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect, + * AVERROR(ENOMEM) if the AVBufferRef cant be created. + */ +int ff_v4l2_buffer_buf_to_avframe(AVFrame *frame, V4L2Buffer *buf); + +/** + * Extracts the data from a V4L2Buffer to an AVPacket + * + * @param[in] pkt The AVPacket to push the information to + * @param[in] buf The V4L2Buffer to get the information from + * + * @returns 0 in case of success, AVERROR(EINVAL) if the number of planes is incorrect, + * AVERROR(ENOMEM) if the AVBufferRef cant be created. + * + */ +int ff_v4l2_buffer_buf_to_avpkt(AVPacket *pkt, V4L2Buffer *buf); + +/** + * Extracts the data from an AVPacket to a V4L2Buffer + * + * @param[in] frame AVPacket to get the data from + * @param[in] avbuf V4L2Bfuffer to push the information to + * + * @returns 0 in case of success, a negative AVERROR code otherwise + */ +int ff_v4l2_buffer_avpkt_to_buf(const AVPacket *pkt, V4L2Buffer *out); + +/** + * Extracts the data from an AVFrame to a V4L2Buffer + * + * @param[in] frame AVFrame to get the data from + * @param[in] avbuf V4L2Bfuffer to push the information to + * + * @returns 0 in case of success, a negative AVERROR code otherwise + */ +int ff_v4l2_buffer_avframe_to_buf(const AVFrame *frame, V4L2Buffer* out); + +/** + * Initializes a V4L2Buffer + * + * @param[in] avbuf V4L2Bfuffer to initialize + * @param[in] index v4l2 buffer id + * + * @returns 0 in case of success, a negative AVERROR code otherwise + */ +int ff_v4l2_buffer_initialize(V4L2Buffer* avbuf, int index); + +/** + * Enqueues a V4L2Buffer + * + * @param[in] avbuf V4L2Bfuffer to push to the driver + * + * @returns 0 in case of success, a negative AVERROR code otherwise + */ +int ff_v4l2_buffer_enqueue(V4L2Buffer* avbuf); + + +#endif // AVCODEC_V4L2_BUFFERS_H |