/*
 * Blackmagic DeckLink output
 * Copyright (c) 2013-2014 Ramiro Polla
 *
 * 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 <atomic>
using std::atomic;

#include <DeckLinkAPI.h>

#include <pthread.h>
#include <semaphore.h>

extern "C" {
#include "libavformat/avformat.h"
#include "libavformat/internal.h"
#include "libavutil/imgutils.h"
}

#include "decklink_common.h"
#include "decklink_enc.h"


/* DeckLink callback class declaration */
class decklink_frame : public IDeckLinkVideoFrame
{
public:
    decklink_frame(struct decklink_ctx *ctx, AVFrame *avframe) :
                   _ctx(ctx), _avframe(avframe),  _refs(1) { }

    virtual long           STDMETHODCALLTYPE GetWidth      (void)          { return _avframe->width; }
    virtual long           STDMETHODCALLTYPE GetHeight     (void)          { return _avframe->height; }
    virtual long           STDMETHODCALLTYPE GetRowBytes   (void)          { return _avframe->linesize[0] < 0 ? -_avframe->linesize[0] : _avframe->linesize[0]; }
    virtual BMDPixelFormat STDMETHODCALLTYPE GetPixelFormat(void)          { return bmdFormat8BitYUV; }
    virtual BMDFrameFlags  STDMETHODCALLTYPE GetFlags      (void)          { return _avframe->linesize[0] < 0 ? bmdFrameFlagFlipVertical : bmdFrameFlagDefault; }
    virtual HRESULT        STDMETHODCALLTYPE GetBytes      (void **buffer)
    {
        if (_avframe->linesize[0] < 0)
            *buffer = (void *)(_avframe->data[0] + _avframe->linesize[0] * (_avframe->height - 1));
        else
            *buffer = (void *)(_avframe->data[0]);
        return S_OK;
    }

    virtual HRESULT STDMETHODCALLTYPE GetTimecode     (BMDTimecodeFormat format, IDeckLinkTimecode **timecode) { return S_FALSE; }
    virtual HRESULT STDMETHODCALLTYPE GetAncillaryData(IDeckLinkVideoFrameAncillary **ancillary)               { return S_FALSE; }

    virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) { return E_NOINTERFACE; }
    virtual ULONG   STDMETHODCALLTYPE AddRef(void)                            { return ++_refs; }
    virtual ULONG   STDMETHODCALLTYPE Release(void)
    {
        int ret = --_refs;
        if (!ret) {
            av_frame_free(&_avframe);
            delete this;
        }
        return ret;
    }

    struct decklink_ctx *_ctx;
    AVFrame *_avframe;

private:
    std::atomic<int>  _refs;
};

class decklink_output_callback : public IDeckLinkVideoOutputCallback
{
public:
    virtual HRESULT STDMETHODCALLTYPE ScheduledFrameCompleted(IDeckLinkVideoFrame *_frame, BMDOutputFrameCompletionResult result)
    {
        decklink_frame *frame = static_cast<decklink_frame *>(_frame);
        struct decklink_ctx *ctx = frame->_ctx;
        AVFrame *avframe = frame->_avframe;

        av_frame_unref(avframe);

        sem_post(&ctx->semaphore);

        return S_OK;
    }
    virtual HRESULT STDMETHODCALLTYPE ScheduledPlaybackHasStopped(void)       { return S_OK; }
    virtual HRESULT STDMETHODCALLTYPE QueryInterface(REFIID iid, LPVOID *ppv) { return E_NOINTERFACE; }
    virtual ULONG   STDMETHODCALLTYPE AddRef(void)                            { return 1; }
    virtual ULONG   STDMETHODCALLTYPE Release(void)                           { return 1; }
};

static int decklink_setup_video(AVFormatContext *avctx, AVStream *st)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
    AVCodecParameters *c = st->codecpar;

    if (ctx->video) {
        av_log(avctx, AV_LOG_ERROR, "Only one video stream is supported!\n");
        return -1;
    }

    if (c->format != AV_PIX_FMT_UYVY422) {
        av_log(avctx, AV_LOG_ERROR, "Unsupported pixel format!"
               " Only AV_PIX_FMT_UYVY422 is supported.\n");
        return -1;
    }
    if (ff_decklink_set_format(avctx, c->width, c->height,
                            st->time_base.num, st->time_base.den, c->field_order)) {
        av_log(avctx, AV_LOG_ERROR, "Unsupported video size, framerate or field order!"
               " Check available formats with -list_formats 1.\n");
        return -1;
    }
    if (ctx->dlo->EnableVideoOutput(ctx->bmd_mode,
                                    bmdVideoOutputFlagDefault) != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not enable video output!\n");
        return -1;
    }

    /* Set callback. */
    ctx->output_callback = new decklink_output_callback();
    ctx->dlo->SetScheduledFrameCompletionCallback(ctx->output_callback);

    /* Start video semaphore. */
    ctx->frames_preroll = st->time_base.den * ctx->preroll;
    if (st->time_base.den > 1000)
        ctx->frames_preroll /= 1000;

    /* Buffer twice as many frames as the preroll. */
    ctx->frames_buffer = ctx->frames_preroll * 2;
    ctx->frames_buffer = FFMIN(ctx->frames_buffer, 60);
    sem_init(&ctx->semaphore, 0, ctx->frames_buffer);

    /* The device expects the framerate to be fixed. */
    avpriv_set_pts_info(st, 64, st->time_base.num, st->time_base.den);

    ctx->video = 1;

    return 0;
}

static int decklink_setup_audio(AVFormatContext *avctx, AVStream *st)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
    AVCodecParameters *c = st->codecpar;

    if (ctx->audio) {
        av_log(avctx, AV_LOG_ERROR, "Only one audio stream is supported!\n");
        return -1;
    }
    if (c->sample_rate != 48000) {
        av_log(avctx, AV_LOG_ERROR, "Unsupported sample rate!"
               " Only 48kHz is supported.\n");
        return -1;
    }
    if (c->channels != 2 && c->channels != 8) {
        av_log(avctx, AV_LOG_ERROR, "Unsupported number of channels!"
               " Only stereo and 7.1 are supported.\n");
        return -1;
    }
    if (ctx->dlo->EnableAudioOutput(bmdAudioSampleRate48kHz,
                                    bmdAudioSampleType16bitInteger,
                                    c->channels,
                                    bmdAudioOutputStreamTimestamped) != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not enable audio output!\n");
        return -1;
    }
    if (ctx->dlo->BeginAudioPreroll() != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not begin audio preroll!\n");
        return -1;
    }

    /* The device expects the sample rate to be fixed. */
    avpriv_set_pts_info(st, 64, 1, c->sample_rate);
    ctx->channels = c->channels;

    ctx->audio = 1;

    return 0;
}

av_cold int ff_decklink_write_trailer(AVFormatContext *avctx)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;

    if (ctx->playback_started) {
        BMDTimeValue actual;
        ctx->dlo->StopScheduledPlayback(ctx->last_pts * ctx->bmd_tb_num,
                                        &actual, ctx->bmd_tb_den);
        ctx->dlo->DisableVideoOutput();
        if (ctx->audio)
            ctx->dlo->DisableAudioOutput();
    }

    ff_decklink_cleanup(avctx);

    if (ctx->output_callback)
        delete ctx->output_callback;

    sem_destroy(&ctx->semaphore);

    av_freep(&cctx->ctx);

    return 0;
}

static int decklink_write_video_packet(AVFormatContext *avctx, AVPacket *pkt)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
    AVFrame *avframe, *tmp = (AVFrame *)pkt->data;
    decklink_frame *frame;
    buffercount_type buffered;
    HRESULT hr;

    if (tmp->format != AV_PIX_FMT_UYVY422 ||
        tmp->width  != ctx->bmd_width ||
        tmp->height != ctx->bmd_height) {
        av_log(avctx, AV_LOG_ERROR, "Got a frame with invalid pixel format or dimension.\n");
        return AVERROR(EINVAL);
    }
    avframe = av_frame_clone(tmp);
    if (!avframe) {
        av_log(avctx, AV_LOG_ERROR, "Could not clone video frame.\n");
        return AVERROR(EIO);
    }

    frame = new decklink_frame(ctx, avframe);
    if (!frame) {
        av_log(avctx, AV_LOG_ERROR, "Could not create new frame.\n");
        av_frame_free(&avframe);
        return AVERROR(EIO);
    }

    /* Always keep at most one second of frames buffered. */
    sem_wait(&ctx->semaphore);

    /* Schedule frame for playback. */
    hr = ctx->dlo->ScheduleVideoFrame((struct IDeckLinkVideoFrame *) frame,
                                      pkt->pts * ctx->bmd_tb_num,
                                      ctx->bmd_tb_num, ctx->bmd_tb_den);
    /* Pass ownership to DeckLink, or release on failure */
    frame->Release();
    if (hr != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not schedule video frame."
                " error %08x.\n", (uint32_t) hr);
        return AVERROR(EIO);
    }

    ctx->dlo->GetBufferedVideoFrameCount(&buffered);
    av_log(avctx, AV_LOG_DEBUG, "Buffered video frames: %d.\n", (int) buffered);
    if (pkt->pts > 2 && buffered <= 2)
        av_log(avctx, AV_LOG_WARNING, "There are not enough buffered video frames."
               " Video may misbehave!\n");

    /* Preroll video frames. */
    if (!ctx->playback_started && pkt->pts > ctx->frames_preroll) {
        av_log(avctx, AV_LOG_DEBUG, "Ending audio preroll.\n");
        if (ctx->audio && ctx->dlo->EndAudioPreroll() != S_OK) {
            av_log(avctx, AV_LOG_ERROR, "Could not end audio preroll!\n");
            return AVERROR(EIO);
        }
        av_log(avctx, AV_LOG_DEBUG, "Starting scheduled playback.\n");
        if (ctx->dlo->StartScheduledPlayback(0, ctx->bmd_tb_den, 1.0) != S_OK) {
            av_log(avctx, AV_LOG_ERROR, "Could not start scheduled playback!\n");
            return AVERROR(EIO);
        }
        ctx->playback_started = 1;
    }

    return 0;
}

static int decklink_write_audio_packet(AVFormatContext *avctx, AVPacket *pkt)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
    int sample_count = pkt->size / (ctx->channels << 1);
    buffercount_type buffered;

    ctx->dlo->GetBufferedAudioSampleFrameCount(&buffered);
    if (pkt->pts > 1 && !buffered)
        av_log(avctx, AV_LOG_WARNING, "There's no buffered audio."
               " Audio will misbehave!\n");

    if (ctx->dlo->ScheduleAudioSamples(pkt->data, sample_count, pkt->pts,
                                       bmdAudioSampleRate48kHz, NULL) != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not schedule audio samples.\n");
        return AVERROR(EIO);
    }

    return 0;
}

extern "C" {

av_cold int ff_decklink_write_header(AVFormatContext *avctx)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx;
    unsigned int n;
    int ret;

    ctx = (struct decklink_ctx *) av_mallocz(sizeof(struct decklink_ctx));
    if (!ctx)
        return AVERROR(ENOMEM);
    ctx->list_devices = cctx->list_devices;
    ctx->list_formats = cctx->list_formats;
    ctx->preroll      = cctx->preroll;
    cctx->ctx = ctx;

    /* List available devices. */
    if (ctx->list_devices) {
        ff_decklink_list_devices(avctx);
        return AVERROR_EXIT;
    }

    ret = ff_decklink_init_device(avctx, avctx->filename);
    if (ret < 0)
        return ret;

    /* Get output device. */
    if (ctx->dl->QueryInterface(IID_IDeckLinkOutput, (void **) &ctx->dlo) != S_OK) {
        av_log(avctx, AV_LOG_ERROR, "Could not open output device from '%s'\n",
               avctx->filename);
        ret = AVERROR(EIO);
        goto error;
    }

    /* List supported formats. */
    if (ctx->list_formats) {
        ff_decklink_list_formats(avctx);
        ret = AVERROR_EXIT;
        goto error;
    }

    /* Setup streams. */
    ret = AVERROR(EIO);
    for (n = 0; n < avctx->nb_streams; n++) {
        AVStream *st = avctx->streams[n];
        AVCodecParameters *c = st->codecpar;
        if        (c->codec_type == AVMEDIA_TYPE_AUDIO) {
            if (decklink_setup_audio(avctx, st))
                goto error;
        } else if (c->codec_type == AVMEDIA_TYPE_VIDEO) {
            if (decklink_setup_video(avctx, st))
                goto error;
        } else {
            av_log(avctx, AV_LOG_ERROR, "Unsupported stream type.\n");
            goto error;
        }
    }

    return 0;

error:
    ff_decklink_cleanup(avctx);
    return ret;
}

int ff_decklink_write_packet(AVFormatContext *avctx, AVPacket *pkt)
{
    struct decklink_cctx *cctx = (struct decklink_cctx *)avctx->priv_data;
    struct decklink_ctx *ctx = (struct decklink_ctx *)cctx->ctx;
    AVStream *st = avctx->streams[pkt->stream_index];

    ctx->last_pts = FFMAX(ctx->last_pts, pkt->pts);

    if      (st->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
        return decklink_write_video_packet(avctx, pkt);
    else if (st->codecpar->codec_type == AVMEDIA_TYPE_AUDIO)
        return decklink_write_audio_packet(avctx, pkt);

    return AVERROR(EIO);
}

} /* extern "C" */
