diff options
Diffstat (limited to 'libavcodec/v4l2_m2m.c')
-rw-r--r-- | libavcodec/v4l2_m2m.c | 406 |
1 files changed, 406 insertions, 0 deletions
diff --git a/libavcodec/v4l2_m2m.c b/libavcodec/v4l2_m2m.c new file mode 100644 index 0000000..427e165 --- /dev/null +++ b/libavcodec/v4l2_m2m.c @@ -0,0 +1,406 @@ +/* + * V4L mem2mem + * + * 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 + */ + +#include <linux/videodev2.h> +#include <sys/ioctl.h> +#include <sys/mman.h> +#include <unistd.h> +#include <dirent.h> +#include <fcntl.h> +#include "libavcodec/avcodec.h" +#include "libavcodec/internal.h" +#include "libavutil/pixdesc.h" +#include "libavutil/imgutils.h" +#include "libavutil/pixfmt.h" +#include "v4l2_context.h" +#include "v4l2_fmt.h" +#include "v4l2_m2m.h" + +static inline int v4l2_splane_video(struct v4l2_capability *cap) +{ + if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE | V4L2_CAP_VIDEO_OUTPUT) && + cap->capabilities & V4L2_CAP_STREAMING) + return 1; + + if (cap->capabilities & V4L2_CAP_VIDEO_M2M) + return 1; + + return 0; +} + +static inline int v4l2_mplane_video(struct v4l2_capability *cap) +{ + if (cap->capabilities & (V4L2_CAP_VIDEO_CAPTURE_MPLANE | V4L2_CAP_VIDEO_OUTPUT_MPLANE) && + cap->capabilities & V4L2_CAP_STREAMING) + return 1; + + if (cap->capabilities & V4L2_CAP_VIDEO_M2M_MPLANE) + return 1; + + return 0; +} + +static int v4l2_prepare_contexts(V4L2m2mContext* s) +{ + struct v4l2_capability cap; + int ret; + + s->capture.done = s->output.done = 0; + s->capture.name = "capture"; + s->output.name = "output "; + atomic_init(&s->refcount, 0); + sem_init(&s->refsync, 0, 0); + + memset(&cap, 0, sizeof(cap)); + ret = ioctl(s->fd, VIDIOC_QUERYCAP, &cap); + if (ret < 0) + return ret; + + av_log(s->avctx, AV_LOG_INFO, "driver '%s' on card '%s'\n", cap.driver, cap.card); + + if (v4l2_mplane_video(&cap)) { + s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE_MPLANE; + s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE; + return 0; + } + + if (v4l2_splane_video(&cap)) { + s->capture.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + s->output.type = V4L2_BUF_TYPE_VIDEO_OUTPUT; + return 0; + } + + return AVERROR(EINVAL); +} + +static int v4l2_probe_driver(V4L2m2mContext* s) +{ + int ret; + + s->fd = open(s->devname, O_RDWR | O_NONBLOCK, 0); + if (s->fd < 0) + return AVERROR(errno); + + ret = v4l2_prepare_contexts(s); + if (ret < 0) + goto done; + + ret = ff_v4l2_context_get_format(&s->output); + if (ret) { + av_log(s->avctx, AV_LOG_DEBUG, "v4l2 output format not supported\n"); + goto done; + } + + ret = ff_v4l2_context_get_format(&s->capture); + if (ret) { + av_log(s->avctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n"); + goto done; + } + +done: + if (close(s->fd) < 0) { + ret = AVERROR(errno); + av_log(s->avctx, AV_LOG_ERROR, "failure closing %s (%s)\n", s->devname, av_err2str(AVERROR(errno))); + } + + s->fd = -1; + + return ret; +} + +static int v4l2_configure_contexts(V4L2m2mContext* s) +{ + void *log_ctx = s->avctx; + int ret; + + s->fd = open(s->devname, O_RDWR | O_NONBLOCK, 0); + if (s->fd < 0) + return AVERROR(errno); + + ret = v4l2_prepare_contexts(s); + if (ret < 0) + goto error; + + ret = ff_v4l2_context_set_format(&s->output); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n"); + goto error; + } + + ret = ff_v4l2_context_set_format(&s->capture); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n"); + goto error; + } + + ret = ff_v4l2_context_init(&s->output); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n"); + goto error; + } + + /* decoder's buffers need to be updated at a later stage */ + if (!av_codec_is_decoder(s->avctx->codec)) { + ret = ff_v4l2_context_init(&s->capture); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n"); + goto error; + } + } + + return 0; + +error: + if (close(s->fd) < 0) { + ret = AVERROR(errno); + av_log(log_ctx, AV_LOG_ERROR, "error closing %s (%s)\n", + s->devname, av_err2str(AVERROR(errno))); + } + s->fd = -1; + + return ret; +} + +/****************************************************************************** + * + * V4L2 M2M Interface + * + ******************************************************************************/ +int ff_v4l2_m2m_codec_reinit(V4L2m2mContext* s) +{ + int ret; + + av_log(s->avctx, AV_LOG_DEBUG, "reinit context\n"); + + /* 1. streamoff */ + ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF); + if (ret) + av_log(s->avctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n"); + + /* 2. unmap the capture buffers (v4l2 and ffmpeg): + * we must wait for all references to be released before being allowed + * to queue new buffers. + */ + av_log(s->avctx, AV_LOG_DEBUG, "waiting for user to release AVBufferRefs\n"); + if (atomic_load(&s->refcount)) + while(sem_wait(&s->refsync) == -1 && errno == EINTR); + + ff_v4l2_context_release(&s->capture); + + /* 3. get the new capture format */ + ret = ff_v4l2_context_get_format(&s->capture); + if (ret) { + av_log(s->avctx, AV_LOG_ERROR, "query the new capture format\n"); + return ret; + } + + /* 4. set the capture format */ + ret = ff_v4l2_context_set_format(&s->capture); + if (ret) { + av_log(s->avctx, AV_LOG_ERROR, "setting capture format\n"); + return ret; + } + + /* 5. complete reinit */ + s->draining = 0; + s->reinit = 0; + + return 0; +} + +int ff_v4l2_m2m_codec_full_reinit(V4L2m2mContext *s) +{ + void *log_ctx = s->avctx; + int ret; + + av_log(log_ctx, AV_LOG_DEBUG, "%s full reinit\n", s->devname); + + /* wait for pending buffer references */ + if (atomic_load(&s->refcount)) + while(sem_wait(&s->refsync) == -1 && errno == EINTR); + + ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF); + if (ret) { + av_log(s->avctx, AV_LOG_ERROR, "output VIDIOC_STREAMOFF\n"); + goto error; + } + + ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF); + if (ret) { + av_log(s->avctx, AV_LOG_ERROR, "capture VIDIOC_STREAMOFF\n"); + goto error; + } + + /* release and unmmap the buffers */ + ff_v4l2_context_release(&s->output); + ff_v4l2_context_release(&s->capture); + + /* start again now that we know the stream dimensions */ + s->draining = 0; + s->reinit = 0; + + ret = ff_v4l2_context_get_format(&s->output); + if (ret) { + av_log(log_ctx, AV_LOG_DEBUG, "v4l2 output format not supported\n"); + goto error; + } + + ret = ff_v4l2_context_get_format(&s->capture); + if (ret) { + av_log(log_ctx, AV_LOG_DEBUG, "v4l2 capture format not supported\n"); + goto error; + } + + ret = ff_v4l2_context_set_format(&s->output); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "can't set v4l2 output format\n"); + goto error; + } + + ret = ff_v4l2_context_set_format(&s->capture); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "can't to set v4l2 capture format\n"); + goto error; + } + + ret = ff_v4l2_context_init(&s->output); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "no v4l2 output context's buffers\n"); + goto error; + } + + /* decoder's buffers need to be updated at a later stage */ + if (!av_codec_is_decoder(s->avctx->codec)) { + ret = ff_v4l2_context_init(&s->capture); + if (ret) { + av_log(log_ctx, AV_LOG_ERROR, "no v4l2 capture context's buffers\n"); + goto error; + } + } + + return 0; + +error: + return ret; +} + +static void v4l2_m2m_destroy_context(void *opaque, uint8_t *context) +{ + V4L2m2mContext *s = (V4L2m2mContext*)context; + + ff_v4l2_context_release(&s->capture); + sem_destroy(&s->refsync); + + close(s->fd); + + av_free(s); +} + +int ff_v4l2_m2m_codec_end(AVCodecContext *avctx) +{ + V4L2m2mPriv *priv = avctx->priv_data; + V4L2m2mContext* s = priv->context; + int ret; + + ret = ff_v4l2_context_set_status(&s->output, VIDIOC_STREAMOFF); + if (ret) + av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->output.name); + + ret = ff_v4l2_context_set_status(&s->capture, VIDIOC_STREAMOFF); + if (ret) + av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMOFF %s\n", s->capture.name); + + ff_v4l2_context_release(&s->output); + + s->self_ref = NULL; + av_buffer_unref(&priv->context_ref); + + return 0; +} + +int ff_v4l2_m2m_codec_init(AVCodecContext *avctx) +{ + int ret = AVERROR(EINVAL); + struct dirent *entry; + char node[PATH_MAX]; + DIR *dirp; + + V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context; + s->avctx = avctx; + + dirp = opendir("/dev"); + if (!dirp) + return AVERROR(errno); + + for (entry = readdir(dirp); entry; entry = readdir(dirp)) { + + if (strncmp(entry->d_name, "video", 5)) + continue; + + snprintf(node, sizeof(node), "/dev/%s", entry->d_name); + av_log(s->avctx, AV_LOG_DEBUG, "probing device %s\n", node); + strncpy(s->devname, node, strlen(node) + 1); + ret = v4l2_probe_driver(s); + if (!ret) + break; + } + + closedir(dirp); + + if (ret) { + av_log(s->avctx, AV_LOG_ERROR, "Could not find a valid device\n"); + memset(s->devname, 0, sizeof(s->devname)); + + return ret; + } + + av_log(s->avctx, AV_LOG_INFO, "Using device %s\n", node); + + return v4l2_configure_contexts(s); +} + +int ff_v4l2_m2m_create_context(AVCodecContext *avctx, V4L2m2mContext **s) +{ + V4L2m2mPriv *priv = avctx->priv_data; + + *s = av_mallocz(sizeof(V4L2m2mContext)); + if (!*s) + return AVERROR(ENOMEM); + + priv->context_ref = av_buffer_create((uint8_t *) *s, sizeof(V4L2m2mContext), + &v4l2_m2m_destroy_context, NULL, 0); + if (!priv->context_ref) { + av_freep(s); + return AVERROR(ENOMEM); + } + + /* assign the context */ + priv->context = *s; + + /* populate it */ + priv->context->capture.num_buffers = priv->num_capture_buffers; + priv->context->output.num_buffers = priv->num_output_buffers; + priv->context->self_ref = priv->context_ref; + + return 0; +} |