/*
 * V4L2 mem2mem encoders
 *
 * 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 <search.h>
#include "libavcodec/avcodec.h"
#include "libavutil/pixdesc.h"
#include "libavutil/pixfmt.h"
#include "libavutil/opt.h"
#include "v4l2_context.h"
#include "v4l2_m2m.h"
#include "v4l2_fmt.h"

#define MPEG_CID(x) V4L2_CID_MPEG_VIDEO_##x
#define MPEG_VIDEO(x) V4L2_MPEG_VIDEO_##x

static inline void v4l2_set_timeperframe(V4L2m2mContext *s, unsigned int num, unsigned int den)
{
    struct v4l2_streamparm parm = { 0 };

    parm.type = V4L2_TYPE_IS_MULTIPLANAR(s->output.type) ? V4L2_BUF_TYPE_VIDEO_OUTPUT_MPLANE : V4L2_BUF_TYPE_VIDEO_OUTPUT;
    parm.parm.output.timeperframe.denominator = den;
    parm.parm.output.timeperframe.numerator = num;

    if (ioctl(s->fd, VIDIOC_S_PARM, &parm) < 0)
        av_log(s->avctx, AV_LOG_WARNING, "Failed to set timeperframe");
}

static inline void v4l2_set_ext_ctrl(V4L2m2mContext *s, unsigned int id, signed int value, const char *name)
{
    struct v4l2_ext_controls ctrls = { { 0 } };
    struct v4l2_ext_control ctrl = { 0 };

    /* set ctrls */
    ctrls.ctrl_class = V4L2_CTRL_CLASS_MPEG;
    ctrls.controls = &ctrl;
    ctrls.count = 1;

    /* set ctrl*/
    ctrl.value = value;
    ctrl.id = id;

    if (ioctl(s->fd, VIDIOC_S_EXT_CTRLS, &ctrls) < 0)
        av_log(s->avctx, AV_LOG_WARNING, "Failed to set %s: %s\n", name, strerror(errno));
    else
        av_log(s->avctx, AV_LOG_DEBUG, "Encoder: %s = %d\n", name, value);
}

static inline int v4l2_get_ext_ctrl(V4L2m2mContext *s, unsigned int id, signed int *value, const char *name)
{
    struct v4l2_ext_controls ctrls = { { 0 } };
    struct v4l2_ext_control ctrl = { 0 };
    int ret;

    /* set ctrls */
    ctrls.ctrl_class = V4L2_CTRL_CLASS_MPEG;
    ctrls.controls = &ctrl;
    ctrls.count = 1;

    /* set ctrl*/
    ctrl.id = id ;

    ret = ioctl(s->fd, VIDIOC_G_EXT_CTRLS, &ctrls);
    if (ret < 0) {
        av_log(s->avctx, AV_LOG_WARNING, "Failed to get %s\n", name);
        return ret;
    }

    *value = ctrl.value;

    return 0;
}

static inline unsigned int v4l2_h264_profile_from_ff(int p)
{
    static const struct h264_profile  {
        unsigned int ffmpeg_val;
        unsigned int v4l2_val;
    } profile[] = {
        { FF_PROFILE_H264_CONSTRAINED_BASELINE, MPEG_VIDEO(H264_PROFILE_CONSTRAINED_BASELINE) },
        { FF_PROFILE_H264_HIGH_444_PREDICTIVE, MPEG_VIDEO(H264_PROFILE_HIGH_444_PREDICTIVE) },
        { FF_PROFILE_H264_HIGH_422_INTRA, MPEG_VIDEO(H264_PROFILE_HIGH_422_INTRA) },
        { FF_PROFILE_H264_HIGH_444_INTRA, MPEG_VIDEO(H264_PROFILE_HIGH_444_INTRA) },
        { FF_PROFILE_H264_HIGH_10_INTRA, MPEG_VIDEO(H264_PROFILE_HIGH_10_INTRA) },
        { FF_PROFILE_H264_HIGH_422, MPEG_VIDEO(H264_PROFILE_HIGH_422) },
        { FF_PROFILE_H264_BASELINE, MPEG_VIDEO(H264_PROFILE_BASELINE) },
        { FF_PROFILE_H264_EXTENDED, MPEG_VIDEO(H264_PROFILE_EXTENDED) },
        { FF_PROFILE_H264_HIGH_10, MPEG_VIDEO(H264_PROFILE_HIGH_10) },
        { FF_PROFILE_H264_MAIN, MPEG_VIDEO(H264_PROFILE_MAIN) },
        { FF_PROFILE_H264_HIGH, MPEG_VIDEO(H264_PROFILE_HIGH) },
    };
    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(profile); i++) {
        if (profile[i].ffmpeg_val == p)
            return profile[i].v4l2_val;
    }
    return AVERROR(ENOENT);
}

static inline int v4l2_mpeg4_profile_from_ff(int p)
{
    static const struct mpeg4_profile {
        unsigned int ffmpeg_val;
        unsigned int v4l2_val;
    } profile[] = {
        { FF_PROFILE_MPEG4_ADVANCED_CODING, MPEG_VIDEO(MPEG4_PROFILE_ADVANCED_CODING_EFFICIENCY) },
        { FF_PROFILE_MPEG4_ADVANCED_SIMPLE, MPEG_VIDEO(MPEG4_PROFILE_ADVANCED_SIMPLE) },
        { FF_PROFILE_MPEG4_SIMPLE_SCALABLE, MPEG_VIDEO(MPEG4_PROFILE_SIMPLE_SCALABLE) },
        { FF_PROFILE_MPEG4_SIMPLE, MPEG_VIDEO(MPEG4_PROFILE_SIMPLE) },
        { FF_PROFILE_MPEG4_CORE, MPEG_VIDEO(MPEG4_PROFILE_CORE) },
    };
    int i;

    for (i = 0; i < FF_ARRAY_ELEMS(profile); i++) {
        if (profile[i].ffmpeg_val == p)
            return profile[i].v4l2_val;
    }
    return AVERROR(ENOENT);
}

static int v4l2_check_b_frame_support(V4L2m2mContext *s)
{
    if (s->avctx->max_b_frames)
        av_log(s->avctx, AV_LOG_WARNING, "Encoder does not support b-frames yet\n");

    v4l2_set_ext_ctrl(s, MPEG_CID(B_FRAMES), 0, "number of B-frames");
    v4l2_get_ext_ctrl(s, MPEG_CID(B_FRAMES), &s->avctx->max_b_frames, "number of B-frames");
    if (s->avctx->max_b_frames == 0)
        return 0;

    avpriv_report_missing_feature(s->avctx, "DTS/PTS calculation for V4L2 encoding");

    return AVERROR_PATCHWELCOME;
}

static inline void v4l2_subscribe_eos_event(V4L2m2mContext *s)
{
    struct v4l2_event_subscription sub;

    memset(&sub, 0, sizeof(sub));
    sub.type = V4L2_EVENT_EOS;
    if (ioctl(s->fd, VIDIOC_SUBSCRIBE_EVENT, &sub) < 0)
        av_log(s->avctx, AV_LOG_WARNING,
               "the v4l2 driver does not support end of stream VIDIOC_SUBSCRIBE_EVENT\n");
}

static int v4l2_prepare_encoder(V4L2m2mContext *s)
{
    AVCodecContext *avctx = s->avctx;
    int qmin_cid, qmax_cid, qmin, qmax;
    int ret, val;

    /**
     * requirements
     */
    v4l2_subscribe_eos_event(s);

    ret = v4l2_check_b_frame_support(s);
    if (ret)
        return ret;

    /**
     * settingss
     */
    if (avctx->framerate.num || avctx->framerate.den)
        v4l2_set_timeperframe(s, avctx->framerate.den, avctx->framerate.num);

    /* set ext ctrls */
    v4l2_set_ext_ctrl(s, MPEG_CID(HEADER_MODE), MPEG_VIDEO(HEADER_MODE_SEPARATE), "header mode");
    v4l2_set_ext_ctrl(s, MPEG_CID(BITRATE) , avctx->bit_rate, "bit rate");
    v4l2_set_ext_ctrl(s, MPEG_CID(GOP_SIZE), avctx->gop_size,"gop size");

    av_log(avctx, AV_LOG_DEBUG,
        "Encoder Context: id (%d), profile (%d), frame rate(%d/%d), number b-frames (%d), "
        "gop size (%d), bit rate (%"PRId64"), qmin (%d), qmax (%d)\n",
        avctx->codec_id, avctx->profile, avctx->framerate.num, avctx->framerate.den,
        avctx->max_b_frames, avctx->gop_size, avctx->bit_rate, avctx->qmin, avctx->qmax);

    switch (avctx->codec_id) {
    case AV_CODEC_ID_H264:
        val = v4l2_h264_profile_from_ff(avctx->profile);
        if (val < 0)
            av_log(avctx, AV_LOG_WARNING, "h264 profile not found\n");
        else
            v4l2_set_ext_ctrl(s, MPEG_CID(H264_PROFILE), val, "h264 profile");
        qmin_cid = MPEG_CID(H264_MIN_QP);
        qmax_cid = MPEG_CID(H264_MAX_QP);
        qmin = 0;
        qmax = 51;
        break;
    case AV_CODEC_ID_MPEG4:
        val = v4l2_mpeg4_profile_from_ff(avctx->profile);
        if (val < 0)
            av_log(avctx, AV_LOG_WARNING, "mpeg4 profile not found\n");
        else
            v4l2_set_ext_ctrl(s, MPEG_CID(MPEG4_PROFILE), val, "mpeg4 profile");
        qmin_cid = MPEG_CID(MPEG4_MIN_QP);
        qmax_cid = MPEG_CID(MPEG4_MAX_QP);
        if (avctx->flags & AV_CODEC_FLAG_QPEL)
            v4l2_set_ext_ctrl(s, MPEG_CID(MPEG4_QPEL), 1, "qpel");
        qmin = 1;
        qmax = 31;
        break;
    case AV_CODEC_ID_H263:
        qmin_cid = MPEG_CID(H263_MIN_QP);
        qmax_cid = MPEG_CID(H263_MAX_QP);
        qmin = 1;
        qmax = 31;
        break;
    case AV_CODEC_ID_VP8:
        qmin_cid = MPEG_CID(VPX_MIN_QP);
        qmax_cid = MPEG_CID(VPX_MAX_QP);
        qmin = 0;
        qmax = 127;
        break;
    case AV_CODEC_ID_VP9:
        qmin_cid = MPEG_CID(VPX_MIN_QP);
        qmax_cid = MPEG_CID(VPX_MAX_QP);
        qmin = 0;
        qmax = 255;
        break;
    default:
        return 0;
    }

    if (qmin != avctx->qmin || qmax != avctx->qmax)
        av_log(avctx, AV_LOG_WARNING, "Encoder adjusted: qmin (%d), qmax (%d)\n", qmin, qmax);

    v4l2_set_ext_ctrl(s, qmin_cid, qmin, "minimum video quantizer scale");
    v4l2_set_ext_ctrl(s, qmax_cid, qmax, "maximum video quantizer scale");

    return 0;
}

static int v4l2_send_frame(AVCodecContext *avctx, const AVFrame *frame)
{
    V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
    V4L2Context *const output = &s->output;

#ifdef V4L2_CID_MPEG_VIDEO_FORCE_KEY_FRAME
    if (frame && frame->pict_type == AV_PICTURE_TYPE_I)
        v4l2_set_ext_ctrl(s, MPEG_CID(FORCE_KEY_FRAME), 0, "force key frame");
#endif

    return ff_v4l2_context_enqueue_frame(output, frame);
}

static int v4l2_receive_packet(AVCodecContext *avctx, AVPacket *avpkt)
{
    V4L2m2mContext *s = ((V4L2m2mPriv*)avctx->priv_data)->context;
    V4L2Context *const capture = &s->capture;
    V4L2Context *const output = &s->output;
    int ret;

    if (s->draining)
        goto dequeue;

    if (!output->streamon) {
        ret = ff_v4l2_context_set_status(output, VIDIOC_STREAMON);
        if (ret) {
            av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMON failed on output context\n");
            return ret;
        }
    }

    if (!capture->streamon) {
        ret = ff_v4l2_context_set_status(capture, VIDIOC_STREAMON);
        if (ret) {
            av_log(avctx, AV_LOG_ERROR, "VIDIOC_STREAMON failed on capture context\n");
            return ret;
        }
    }

dequeue:
    return ff_v4l2_context_dequeue_packet(capture, avpkt);
}

static av_cold int v4l2_encode_init(AVCodecContext *avctx)
{
    V4L2Context *capture, *output;
    V4L2m2mContext *s;
    V4L2m2mPriv *priv = avctx->priv_data;
    enum AVPixelFormat pix_fmt_output;
    uint32_t v4l2_fmt_output;
    int ret;

    ret = ff_v4l2_m2m_create_context(priv, &s);
    if (ret < 0)
        return ret;

    capture = &s->capture;
    output  = &s->output;

    /* common settings output/capture */
    output->height = capture->height = avctx->height;
    output->width = capture->width = avctx->width;

    /* output context */
    output->av_codec_id = AV_CODEC_ID_RAWVIDEO;
    output->av_pix_fmt = avctx->pix_fmt;

    /* capture context */
    capture->av_codec_id = avctx->codec_id;
    capture->av_pix_fmt = AV_PIX_FMT_NONE;

    s->avctx = avctx;
    ret = ff_v4l2_m2m_codec_init(priv);
    if (ret) {
        av_log(avctx, AV_LOG_ERROR, "can't configure encoder\n");
        return ret;
    }

    if (V4L2_TYPE_IS_MULTIPLANAR(output->type))
        v4l2_fmt_output = output->format.fmt.pix_mp.pixelformat;
    else
        v4l2_fmt_output = output->format.fmt.pix.pixelformat;

    pix_fmt_output = ff_v4l2_format_v4l2_to_avfmt(v4l2_fmt_output, AV_CODEC_ID_RAWVIDEO);
    if (pix_fmt_output != avctx->pix_fmt) {
        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(pix_fmt_output);
        av_log(avctx, AV_LOG_ERROR, "Encoder requires %s pixel format.\n", desc->name);
        return AVERROR(EINVAL);
    }

    return v4l2_prepare_encoder(s);
}

static av_cold int v4l2_encode_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_ENCODING_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 = 4 }, 4, INT_MAX, FLAGS },
    { NULL },
};

#define M2MENC_CLASS(NAME) \
    static const AVClass v4l2_m2m_ ## NAME ## _enc_class = { \
        .class_name = #NAME "_v4l2m2m_encoder", \
        .item_name  = av_default_item_name, \
        .option     = options, \
        .version    = LIBAVUTIL_VERSION_INT, \
    };

#define M2MENC(NAME, LONGNAME, CODEC) \
    M2MENC_CLASS(NAME) \
    AVCodec ff_ ## NAME ## _v4l2m2m_encoder = { \
        .name           = #NAME "_v4l2m2m" , \
        .long_name      = NULL_IF_CONFIG_SMALL("V4L2 mem2mem " LONGNAME " encoder wrapper"), \
        .type           = AVMEDIA_TYPE_VIDEO, \
        .id             = CODEC , \
        .priv_data_size = sizeof(V4L2m2mPriv), \
        .priv_class     = &v4l2_m2m_ ## NAME ##_enc_class, \
        .init           = v4l2_encode_init, \
        .send_frame     = v4l2_send_frame, \
        .receive_packet = v4l2_receive_packet, \
        .close          = v4l2_encode_close, \
        .capabilities   = AV_CODEC_CAP_HARDWARE | AV_CODEC_CAP_DELAY, \
        .wrapper_name   = "v4l2m2m", \
    };

M2MENC(mpeg4,"MPEG4", AV_CODEC_ID_MPEG4);
M2MENC(h263, "H.263", AV_CODEC_ID_H263);
M2MENC(h264, "H.264", AV_CODEC_ID_H264);
M2MENC(hevc, "HEVC",  AV_CODEC_ID_HEVC);
M2MENC(vp8,  "VP8",   AV_CODEC_ID_VP8);