/*
 * Intel MediaSDK QSV based HEVC encoder
 *
 * 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 <stdint.h>
#include <sys/types.h>

#include <mfx/mfxvideo.h>

#include "libavutil/common.h"
#include "libavutil/opt.h"

#include "avcodec.h"
#include "bytestream.h"
#include "get_bits.h"
#include "hevc.h"
#include "internal.h"
#include "qsv.h"
#include "qsv_internal.h"
#include "qsvenc.h"

enum LoadPlugin {
    LOAD_PLUGIN_NONE,
    LOAD_PLUGIN_HEVC_SW,
    LOAD_PLUGIN_HEVC_HW,
};

typedef struct QSVHEVCEncContext {
    AVClass *class;
    QSVEncContext qsv;
    int load_plugin;
} QSVHEVCEncContext;

static int generate_fake_vps(QSVEncContext *q, AVCodecContext *avctx)
{
    GetByteContext gbc;
    PutByteContext pbc;

    GetBitContext gb;
    HEVCNAL sps_nal = { NULL };
    HEVCSPS sps = { 0 };
    HEVCVPS vps = { 0 };
    uint8_t vps_buf[128], vps_rbsp_buf[128];
    uint8_t *new_extradata;
    unsigned int sps_id;
    int ret, i, type, vps_size;

    if (!avctx->extradata_size) {
        av_log(avctx, AV_LOG_ERROR, "No extradata returned from libmfx\n");
        return AVERROR_UNKNOWN;
    }

    /* parse the SPS */
    ret = ff_hevc_extract_rbsp(NULL, avctx->extradata + 4, avctx->extradata_size - 4, &sps_nal);
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error unescaping the SPS buffer\n");
        return ret;
    }

    ret = init_get_bits8(&gb, sps_nal.data, sps_nal.size);
    if (ret < 0) {
        av_freep(&sps_nal.rbsp_buffer);
        return ret;
    }

    get_bits(&gb, 1);
    type = get_bits(&gb, 6);
    if (type != NAL_SPS) {
        av_log(avctx, AV_LOG_ERROR, "Unexpected NAL type in the extradata: %d\n",
               type);
        av_freep(&sps_nal.rbsp_buffer);
        return AVERROR_INVALIDDATA;
    }
    get_bits(&gb, 9);

    ret = ff_hevc_parse_sps(&sps, &gb, &sps_id, 0, NULL, avctx);
    av_freep(&sps_nal.rbsp_buffer);
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error parsing the SPS\n");
        return ret;
    }

    /* generate the VPS */
    vps.vps_max_layers     = 1;
    vps.vps_max_sub_layers = sps.max_sub_layers;
    memcpy(&vps.ptl, &sps.ptl, sizeof(vps.ptl));
    vps.vps_sub_layer_ordering_info_present_flag = 1;
    for (i = 0; i < MAX_SUB_LAYERS; i++) {
        vps.vps_max_dec_pic_buffering[i] = sps.temporal_layer[i].max_dec_pic_buffering;
        vps.vps_num_reorder_pics[i]      = sps.temporal_layer[i].num_reorder_pics;
        vps.vps_max_latency_increase[i]  = sps.temporal_layer[i].max_latency_increase;
    }

    vps.vps_num_layer_sets                  = 1;
    vps.vps_timing_info_present_flag        = sps.vui.vui_timing_info_present_flag;
    vps.vps_num_units_in_tick               = sps.vui.vui_num_units_in_tick;
    vps.vps_time_scale                      = sps.vui.vui_time_scale;
    vps.vps_poc_proportional_to_timing_flag = sps.vui.vui_poc_proportional_to_timing_flag;
    vps.vps_num_ticks_poc_diff_one          = sps.vui.vui_num_ticks_poc_diff_one_minus1 + 1;

    /* generate the encoded RBSP form of the VPS */
    ret = ff_hevc_encode_nal_vps(&vps, sps.vps_id, vps_rbsp_buf, sizeof(vps_rbsp_buf));
    if (ret < 0) {
        av_log(avctx, AV_LOG_ERROR, "Error writing the VPS\n");
        return ret;
    }

    /* escape and add the startcode */
    bytestream2_init(&gbc, vps_rbsp_buf, ret);
    bytestream2_init_writer(&pbc, vps_buf, sizeof(vps_buf));

    bytestream2_put_be32(&pbc, 1);              // startcode
    bytestream2_put_byte(&pbc, NAL_VPS << 1);   // NAL
    bytestream2_put_byte(&pbc, 1);              // header

    while (bytestream2_get_bytes_left(&gbc)) {
        uint32_t b = bytestream2_peek_be24(&gbc);
        if (b <= 3) {
            bytestream2_put_be24(&pbc, 3);
            bytestream2_skip(&gbc, 2);
        } else
            bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc));
    }

    vps_size = bytestream2_tell_p(&pbc);
    new_extradata = av_mallocz(vps_size + avctx->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
    if (!new_extradata)
        return AVERROR(ENOMEM);
    memcpy(new_extradata, vps_buf, vps_size);
    memcpy(new_extradata + vps_size, avctx->extradata, avctx->extradata_size);

    av_freep(&avctx->extradata);
    avctx->extradata       = new_extradata;
    avctx->extradata_size += vps_size;

    return 0;
}

static av_cold int qsv_enc_init(AVCodecContext *avctx)
{
    QSVHEVCEncContext *q = avctx->priv_data;
    int ret;

    if (q->load_plugin != LOAD_PLUGIN_NONE) {
        static const char *uid_hevcenc_sw = "2fca99749fdb49aeb121a5b63ef568f7";
        static const char *uid_hevcenc_hw = "6fadc791a0c2eb479ab6dcd5ea9da347";

        if (q->qsv.load_plugins[0]) {
            av_log(avctx, AV_LOG_WARNING,
                   "load_plugins is not empty, but load_plugin is not set to 'none'."
                   "The load_plugin value will be ignored.\n");
        } else {
            av_freep(&q->qsv.load_plugins);

            if (q->load_plugin == LOAD_PLUGIN_HEVC_SW)
                q->qsv.load_plugins = av_strdup(uid_hevcenc_sw);
            else
                q->qsv.load_plugins = av_strdup(uid_hevcenc_hw);

            if (!q->qsv.load_plugins)
                return AVERROR(ENOMEM);
        }
    }

    ret = ff_qsv_enc_init(avctx, &q->qsv);
    if (ret < 0)
        return ret;

    ret = generate_fake_vps(&q->qsv, avctx);
    if (ret < 0) {
        ff_qsv_enc_close(avctx, &q->qsv);
        return ret;
    }

    return 0;
}

static int qsv_enc_frame(AVCodecContext *avctx, AVPacket *pkt,
                         const AVFrame *frame, int *got_packet)
{
    QSVHEVCEncContext *q = avctx->priv_data;

    return ff_qsv_encode(avctx, &q->qsv, pkt, frame, got_packet);
}

static av_cold int qsv_enc_close(AVCodecContext *avctx)
{
    QSVHEVCEncContext *q = avctx->priv_data;

    return ff_qsv_enc_close(avctx, &q->qsv);
}

#define OFFSET(x) offsetof(QSVHEVCEncContext, x)
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
static const AVOption options[] = {
    QSV_COMMON_OPTS

    { "load_plugin", "A user plugin to load in an internal session", OFFSET(load_plugin), AV_OPT_TYPE_INT, { .i64 = LOAD_PLUGIN_HEVC_SW }, LOAD_PLUGIN_NONE, LOAD_PLUGIN_HEVC_HW, VE, "load_plugin" },
    { "none",     NULL, 0, AV_OPT_TYPE_CONST, { .i64 = LOAD_PLUGIN_NONE },    0, 0, VE, "load_plugin" },
    { "hevc_sw",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = LOAD_PLUGIN_HEVC_SW }, 0, 0, VE, "load_plugin" },
    { "hevc_hw",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = LOAD_PLUGIN_HEVC_HW }, 0, 0, VE, "load_plugin" },

    { "load_plugins", "A :-separate list of hexadecimal plugin UIDs to load in an internal session",
        OFFSET(qsv.load_plugins), AV_OPT_TYPE_STRING, { .str = "" }, 0, 0, VE },

    { "profile", NULL, OFFSET(qsv.profile), AV_OPT_TYPE_INT, { .i64 = MFX_PROFILE_UNKNOWN }, 0, INT_MAX, VE, "profile" },
    { "unknown", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_PROFILE_UNKNOWN      }, INT_MIN, INT_MAX,     VE, "profile" },
    { "main",    NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_PROFILE_HEVC_MAIN    }, INT_MIN, INT_MAX,     VE, "profile" },
    { "main10",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_PROFILE_HEVC_MAIN10  }, INT_MIN, INT_MAX,     VE, "profile" },
    { "mainsp",  NULL, 0, AV_OPT_TYPE_CONST, { .i64 = MFX_PROFILE_HEVC_MAINSP  }, INT_MIN, INT_MAX,     VE, "profile" },

    { NULL },
};

static const AVClass class = {
    .class_name = "hevc_qsv encoder",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

static const AVCodecDefault qsv_enc_defaults[] = {
    { "b",         "1M"    },
    { "refs",      "0"     },
    // same as the x264 default
    { "g",         "248"   },
    { "bf",        "8"     },

    { "flags",     "+cgop" },
#if FF_API_PRIVATE_OPT
    { "b_strategy", "-1"   },
#endif
    { NULL },
};

AVCodec ff_hevc_qsv_encoder = {
    .name           = "hevc_qsv",
    .long_name      = NULL_IF_CONFIG_SMALL("HEVC (Intel Quick Sync Video acceleration)"),
    .priv_data_size = sizeof(QSVHEVCEncContext),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_HEVC,
    .init           = qsv_enc_init,
    .encode2        = qsv_enc_frame,
    .close          = qsv_enc_close,
    .capabilities   = AV_CODEC_CAP_DELAY,
    .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_NV12,
                                                    AV_PIX_FMT_QSV,
                                                    AV_PIX_FMT_NONE },
    .priv_class     = &class,
    .defaults       = qsv_enc_defaults,
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
};