| /* |
| * V4L2 context 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_CONTEXT_H |
| #define AVCODEC_V4L2_CONTEXT_H |
| |
| #include <stdatomic.h> |
| #include <linux/videodev2.h> |
| |
| #include "libavcodec/avcodec.h" |
| #include "libavutil/pixfmt.h" |
| #include "libavutil/frame.h" |
| #include "libavutil/buffer.h" |
| #include "v4l2_buffers.h" |
| |
| typedef struct V4L2Context { |
| /** |
| * context name. |
| */ |
| const char* name; |
| |
| /** |
| * Type of this buffer context. |
| * See V4L2_BUF_TYPE_VIDEO_* in videodev2.h |
| * Readonly after init. |
| */ |
| enum v4l2_buf_type type; |
| |
| /** |
| * AVPixelFormat corresponding to this buffer context. |
| * AV_PIX_FMT_NONE means this is an encoded stream. |
| */ |
| enum AVPixelFormat av_pix_fmt; |
| |
| /** |
| * AVCodecID corresponding to this buffer context. |
| * AV_CODEC_ID_RAWVIDEO means this is a raw stream and av_pix_fmt must be set to a valid value. |
| */ |
| enum AVCodecID av_codec_id; |
| |
| /** |
| * Format returned by the driver after initializing the buffer context. |
| * Readonly after init. |
| */ |
| struct v4l2_format format; |
| |
| /** |
| * Width and height of the frames it produces (in case of a capture context, e.g. when decoding) |
| * or accepts (in case of an output context, e.g. when encoding). |
| */ |
| int width, height; |
| AVRational sample_aspect_ratio; |
| |
| /** |
| * Indexed array of V4L2Buffers |
| */ |
| V4L2Buffer *buffers; |
| |
| /** |
| * Readonly after init. |
| */ |
| int num_buffers; |
| |
| /** |
| * Whether the stream has been started (VIDIOC_STREAMON has been sent). |
| */ |
| int streamon; |
| |
| /** |
| * Either no more buffers available or an unrecoverable error was notified |
| * by the V4L2 kernel driver: once set the context has to be exited. |
| */ |
| int done; |
| |
| } V4L2Context; |
| |
| /** |
| * Initializes a V4L2Context. |
| * |
| * @param[in] ctx A pointer to a V4L2Context. See V4L2Context description for required variables. |
| * @return 0 in case of success, a negative value representing the error otherwise. |
| */ |
| int ff_v4l2_context_init(V4L2Context* ctx); |
| |
| /** |
| * Sets the V4L2Context format in the v4l2 driver. |
| * |
| * @param[in] ctx A pointer to a V4L2Context. See V4L2Context description for required variables. |
| * @return 0 in case of success, a negative value representing the error otherwise. |
| */ |
| int ff_v4l2_context_set_format(V4L2Context* ctx); |
| |
| /** |
| * Queries the driver for a valid v4l2 format and copies it to the context. |
| * |
| * @param[in] ctx A pointer to a V4L2Context. See V4L2Context description for required variables. |
| * @param[in] probe Probe only and ignore changes to the format. |
| * @return 0 in case of success, a negative value representing the error otherwise. |
| */ |
| int ff_v4l2_context_get_format(V4L2Context* ctx, int probe); |
| |
| /** |
| * Releases a V4L2Context. |
| * |
| * @param[in] ctx A pointer to a V4L2Context. |
| * The caller is reponsible for freeing it. |
| * It must not be used after calling this function. |
| */ |
| void ff_v4l2_context_release(V4L2Context* ctx); |
| |
| /** |
| * Sets the status of a V4L2Context. |
| * |
| * @param[in] ctx A pointer to a V4L2Context. |
| * @param[in] cmd The status to set (VIDIOC_STREAMON or VIDIOC_STREAMOFF). |
| * Warning: If VIDIOC_STREAMOFF is sent to a buffer context that still has some frames buffered, |
| * those frames will be dropped. |
| * @return 0 in case of success, a negative value representing the error otherwise. |
| */ |
| int ff_v4l2_context_set_status(V4L2Context* ctx, uint32_t cmd); |
| |
| /** |
| * Dequeues a buffer from a V4L2Context to an AVPacket. |
| * |
| * The pkt must be non NULL. |
| * @param[in] ctx The V4L2Context to dequeue from. |
| * @param[inout] pkt The AVPacket to dequeue to. |
| * @return 0 in case of success, AVERROR(EAGAIN) if no buffer was ready, another negative error in case of error. |
| */ |
| int ff_v4l2_context_dequeue_packet(V4L2Context* ctx, AVPacket* pkt); |
| |
| /** |
| * Dequeues a buffer from a V4L2Context to an AVFrame. |
| * |
| * The frame must be non NULL. |
| * @param[in] ctx The V4L2Context to dequeue from. |
| * @param[inout] f The AVFrame to dequeue to. |
| * @param[in] timeout The timeout for dequeue (-1 to block, 0 to return immediately, or milliseconds) |
| * @return 0 in case of success, AVERROR(EAGAIN) if no buffer was ready, another negative error in case of error. |
| */ |
| int ff_v4l2_context_dequeue_frame(V4L2Context* ctx, AVFrame* f, int timeout); |
| |
| /** |
| * Enqueues a buffer to a V4L2Context from an AVPacket |
| * |
| * The packet must be non NULL. |
| * When the size of the pkt is null, the buffer is not queued but a V4L2_DEC_CMD_STOP command is sent instead to the driver. |
| * |
| * @param[in] ctx The V4L2Context to enqueue to. |
| * @param[in] pkt A pointer to an AVPacket. |
| * @return 0 in case of success, a negative error otherwise. |
| */ |
| int ff_v4l2_context_enqueue_packet(V4L2Context* ctx, const AVPacket* pkt); |
| |
| /** |
| * Enqueues a buffer to a V4L2Context from an AVFrame |
| * |
| * The frame must be non NULL. |
| * |
| * @param[in] ctx The V4L2Context to enqueue to. |
| * @param[in] f A pointer to an AVFrame to enqueue. |
| * @return 0 in case of success, a negative error otherwise. |
| */ |
| int ff_v4l2_context_enqueue_frame(V4L2Context* ctx, const AVFrame* f); |
| |
| #endif // AVCODEC_V4L2_CONTEXT_H |