diff options
Diffstat (limited to 'libavcodec/v4l2_m2m_dec.c')
-rw-r--r-- | libavcodec/v4l2_m2m_dec.c | 236 |
1 files changed, 236 insertions, 0 deletions
diff --git a/libavcodec/v4l2_m2m_dec.c b/libavcodec/v4l2_m2m_dec.c new file mode 100644 index 0000000..bca45be --- /dev/null +++ b/libavcodec/v4l2_m2m_dec.c @@ -0,0 +1,236 @@ +/* + * V4L2 mem2mem decoders + * + * 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 "libavutil/pixfmt.h" +#include "libavutil/pixdesc.h" +#include "libavutil/opt.h" +#include "libavcodec/avcodec.h" +#include "libavcodec/decode.h" + +#include "v4l2_context.h" +#include "v4l2_m2m.h" +#include "v4l2_fmt.h" + +static int v4l2_try_start(AVCodecContext *avctx) +{ + V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context; + V4L2Context *const capture = &s->capture; + V4L2Context *const output = &s->output; + struct v4l2_selection selection; + int ret; + + /* 1. start the output process */ + if (!output->streamon) { + ret = ff_v4l2_context_set_status(output, VIDIOC_STREAMON); + if (ret < 0) { + av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON on output context\n"); + return ret; + } + } + + if (capture->streamon) + return 0; + + /* 2. get the capture format */ + capture->format.type = capture->type; + ret = ioctl(s->fd, VIDIOC_G_FMT, &capture->format); + if (ret) { + av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_FMT ioctl\n"); + return ret; + } + + /* 2.1 update the AVCodecContext */ + avctx->pix_fmt = ff_v4l2_format_v4l2_to_avfmt(capture->format.fmt.pix_mp.pixelformat, AV_CODEC_ID_RAWVIDEO); + capture->av_pix_fmt = avctx->pix_fmt; + + /* 3. set the crop parameters */ + selection.type = V4L2_BUF_TYPE_VIDEO_CAPTURE; + selection.r.height = avctx->coded_height; + selection.r.width = avctx->coded_width; + ret = ioctl(s->fd, VIDIOC_S_SELECTION, &selection); + if (!ret) { + ret = ioctl(s->fd, VIDIOC_G_SELECTION, &selection); + if (ret) { + av_log(avctx, AV_LOG_WARNING, "VIDIOC_G_SELECTION ioctl\n"); + } else { + av_log(avctx, AV_LOG_DEBUG, "crop output %dx%d\n", selection.r.width, selection.r.height); + /* update the size of the resulting frame */ + capture->height = selection.r.height; + capture->width = selection.r.width; + } + } + + /* 4. init the capture context now that we have the capture format */ + if (!capture->buffers) { + ret = ff_v4l2_context_init(capture); + if (ret) { + av_log(avctx, AV_LOG_DEBUG, "can't request output buffers\n"); + return ret; + } + } + + /* 5. start the capture process */ + ret = ff_v4l2_context_set_status(capture, VIDIOC_STREAMON); + if (ret) { + av_log(avctx, AV_LOG_DEBUG, "VIDIOC_STREAMON, on capture context\n"); + return ret; + } + + return 0; +} + +static int v4l2_prepare_decoder(V4L2m2mContext *s) +{ + struct v4l2_event_subscription sub; + V4L2Context *output = &s->output; + int ret; + + /** + * requirements + */ + memset(&sub, 0, sizeof(sub)); + sub.type = V4L2_EVENT_SOURCE_CHANGE; + ret = ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub); + if ( ret < 0) { + if (output->height == 0 || output->width == 0) { + av_log(s->avctx, AV_LOG_ERROR, + "the v4l2 driver does not support VIDIOC_SUBSCRIBE_EVENT\n" + "you must provide codec_height and codec_width on input\n"); + return ret; + } + } + + return 0; +} + +static int v4l2_receive_frame(AVCodecContext *avctx, AVFrame *frame) +{ + V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context; + V4L2Context *const capture = &s->capture; + V4L2Context *const output = &s->output; + AVPacket avpkt = {0}; + int ret; + + ret = ff_decode_get_packet(avctx, &avpkt); + if (ret < 0 && ret != AVERROR_EOF) + return ret; + + if (s->draining) + goto dequeue; + + ret = ff_v4l2_context_enqueue_packet(output, &avpkt); + if (ret < 0) { + if (ret != AVERROR(ENOMEM)) + return ret; + /* no input buffers available, continue dequeing */ + } + + if (avpkt.size) { + ret = v4l2_try_start(avctx); + if (ret) + return 0; + } + +dequeue: + return ff_v4l2_context_dequeue_frame(capture, frame); +} + +static av_cold int v4l2_decode_init(AVCodecContext *avctx) +{ + V4L2Context *capture, *output; + V4L2m2mContext *s; + int ret; + + ret = ff_v4l2_m2m_create_context(avctx, &s); + if (ret < 0) + return ret; + + capture = &s->capture; + output = &s->output; + + /* if these dimensions are invalid (ie, 0 or too small) an event will be raised + * by the v4l2 driver; this event will trigger a full pipeline reconfig and + * the proper values will be retrieved from the kernel driver. + */ + output->height = capture->height = avctx->coded_height; + output->width = capture->width = avctx->coded_width; + + output->av_codec_id = avctx->codec_id; + output->av_pix_fmt = AV_PIX_FMT_NONE; + + capture->av_codec_id = AV_CODEC_ID_RAWVIDEO; + capture->av_pix_fmt = avctx->pix_fmt; + + ret = ff_v4l2_m2m_codec_init(avctx); + if (ret) { + av_log(avctx, AV_LOG_ERROR, "can't configure decoder\n"); + return ret; + } + + return v4l2_prepare_decoder(s); +} + +#define OFFSET(x) offsetof(V4L2m2mPriv, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_DECODING_PARAM + +static const AVOption options[] = { + V4L_M2M_DEFAULT_OPTS, + { "num_capture_buffers", "Number of buffers in the capture context", + OFFSET(num_capture_buffers), AV_OPT_TYPE_INT, {.i64 = 20}, 20, INT_MAX, FLAGS }, + { NULL}, +}; + +#define M2MDEC(NAME, LONGNAME, CODEC, bsf_name) \ +static const AVClass v4l2_m2m_ ## NAME ## _dec_class = {\ + .class_name = #NAME "_v4l2_m2m_decoder",\ + .item_name = av_default_item_name,\ + .option = options,\ + .version = LIBAVUTIL_VERSION_INT,\ +};\ +\ +AVCodec ff_ ## NAME ## _v4l2m2m_decoder = { \ + .name = #NAME "_v4l2m2m" ,\ + .long_name = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " decoder wrapper"),\ + .type = AVMEDIA_TYPE_VIDEO,\ + .id = CODEC ,\ + .priv_data_size = sizeof(V4L2m2mPriv),\ + .priv_class = &v4l2_m2m_ ## NAME ## _dec_class,\ + .init = v4l2_decode_init,\ + .receive_frame = v4l2_receive_frame,\ + .close = ff_v4l2_m2m_codec_end,\ + .bsfs = bsf_name, \ + .capabilities = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY, \ + .wrapper_name = "v4l2m2m", \ +}; + +M2MDEC(h264, "H.264", AV_CODEC_ID_H264, "h264_mp4toannexb"); +M2MDEC(hevc, "HEVC", AV_CODEC_ID_HEVC, "hevc_mp4toannexb"); +M2MDEC(mpeg1, "MPEG1", AV_CODEC_ID_MPEG1VIDEO, NULL); +M2MDEC(mpeg2, "MPEG2", AV_CODEC_ID_MPEG2VIDEO, NULL); +M2MDEC(mpeg4, "MPEG4", AV_CODEC_ID_MPEG4, NULL); +M2MDEC(h263, "H.263", AV_CODEC_ID_H263, NULL); +M2MDEC(vc1 , "VC1", AV_CODEC_ID_VC1, NULL); +M2MDEC(vp8, "VP8", AV_CODEC_ID_VP8, NULL); +M2MDEC(vp9, "VP9", AV_CODEC_ID_VP9, NULL); |