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ffmpeg/libavcodec/v4l2_m2m_dec.c

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/*
* 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 "codec_internal.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 = { 0 };
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_ERROR, "can't request capture buffers\n");
return AVERROR(ENOMEM);
}
}
/* 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;
}
}
memset(&sub, 0, sizeof(sub));
sub.type = V4L2_EVENT_EOS;
ret = ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub);
if (ret < 0)
av_log(s->avctx, AV_LOG_WARNING,
"the v4l2 driver does not support end of stream VIDIOC_SUBSCRIBE_EVENT\n");
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;
int ret;
if (!s->buf_pkt.size) {
ret = ff_decode_get_packet(avctx, &s->buf_pkt);
if (ret < 0) {
if (ret == AVERROR(EAGAIN))
return ff_v4l2_context_dequeue_frame(capture, frame, 0);
else if (ret != AVERROR_EOF)
return ret;
}
}
if (s->draining)
goto dequeue;
ret = ff_v4l2_context_enqueue_packet(output, &s->buf_pkt);
if (ret < 0 && ret != AVERROR(EAGAIN))
goto fail;
/* if EAGAIN don't unref packet and try to enqueue in the next iteration */
if (ret != AVERROR(EAGAIN))
av_packet_unref(&s->buf_pkt);
if (!s->draining) {
ret = v4l2_try_start(avctx);
if (ret) {
/* cant recover */
if (ret != AVERROR(ENOMEM))
ret = 0;
goto fail;
}
}
dequeue:
return ff_v4l2_context_dequeue_frame(capture, frame, -1);
fail:
av_packet_unref(&s->buf_pkt);
return ret;
}
static av_cold int v4l2_decode_init(AVCodecContext *avctx)
{
V4L2Context *capture, *output;
V4L2m2mContext *s;
V4L2m2mPriv *priv = avctx->priv_data;
int ret;
ret = ff_v4l2_m2m_create_context(priv, &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;
s->avctx = avctx;
ret = ff_v4l2_m2m_codec_init(priv);
if (ret) {
av_log(avctx, AV_LOG_ERROR, "can't configure decoder\n");
return ret;
}
return v4l2_prepare_decoder(s);
}
static av_cold int v4l2_decode_close(AVCodecContext *avctx)
{
return ff_v4l2_m2m_codec_end(avctx->priv_data);
}
#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}, 2, INT_MAX, FLAGS },
{ NULL},
};
#define M2MDEC_CLASS(NAME) \
static const AVClass v4l2_m2m_ ## NAME ## _dec_class = { \
.class_name = #NAME "_v4l2m2m_decoder", \
.item_name = av_default_item_name, \
.option = options, \
.version = LIBAVUTIL_VERSION_INT, \
};
#define M2MDEC(NAME, LONGNAME, CODEC, bsf_name) \
M2MDEC_CLASS(NAME) \
const FFCodec ff_ ## NAME ## _v4l2m2m_decoder = { \
.p.name = #NAME "_v4l2m2m" , \
CODEC_LONG_NAME("V4L2 mem2mem " LONGNAME " decoder wrapper"), \
.p.type = AVMEDIA_TYPE_VIDEO, \
.p.id = CODEC , \
.priv_data_size = sizeof(V4L2m2mPriv), \
.p.priv_class = &v4l2_m2m_ ## NAME ## _dec_class, \
.init = v4l2_decode_init, \
FF_CODEC_RECEIVE_FRAME_CB(v4l2_receive_frame), \
.close = v4l2_decode_close, \
.bsfs = bsf_name, \
.p.capabilities = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AVOID_PROBING, \
.caps_internal = FF_CODEC_CAP_NOT_INIT_THREADSAFE | \
FF_CODEC_CAP_SETS_PKT_DTS | FF_CODEC_CAP_INIT_CLEANUP, \
.p.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);
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