decklink_dec.cpp

/*
 * Blackmagic DeckLink input
 * Copyright (c) 2013-2014 Luca Barbato, Deti Fliegl
 * Copyright (c) 2014 Rafaël Carré
 * Copyright (c) 2017 Akamai Technologies, Inc.
 *
 * 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 internal.h first to avoid conflict between winsock.h (used by
 * DeckLink headers) and winsock2.h (used by libavformat) in MSVC++ builds */
extern "C" {
#include "libavformat/internal.h"
}

#include <DeckLinkAPI.h>

extern "C" {
#include "config.h"
#include "libavformat/avformat.h"
#include "libavutil/avassert.h"
#include "libavutil/avutil.h"
#include "libavutil/common.h"
#include "libavutil/imgutils.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/time.h"
#include "libavutil/mathematics.h"
#include "libavutil/reverse.h"
#include "avdevice.h"
#if CONFIG_LIBZVBI
#include <libzvbi.h>
#endif
}

#include "decklink_common.h"
#include "decklink_dec.h"

#define MAX_WIDTH_VANC 1920
const BMDDisplayMode AUTODETECT_DEFAULT_MODE = bmdModeNTSC;

typedef struct VANCLineNumber {
    BMDDisplayMode mode;
    int vanc_start;
    int field0_vanc_end;
    int field1_vanc_start;
    int vanc_end;
} VANCLineNumber;

/* These VANC line numbers need not be very accurate. In any case
 * GetBufferForVerticalBlankingLine() will return an error when invalid
 * ancillary line number was requested. We just need to make sure that the
 * entire VANC region is covered, while making sure we don't decode VANC of
 * another source during switching*/
static VANCLineNumber vanc_line_numbers[] = {
    /* SD Modes */

    {bmdModeNTSC, 11, 19, 274, 282},
    {bmdModeNTSC2398, 11, 19, 274, 282},
    {bmdModePAL, 7, 22, 320, 335},
    {bmdModeNTSCp, 11, -1, -1, 39},
    {bmdModePALp, 7, -1, -1, 45},

    /* HD 1080 Modes */

    {bmdModeHD1080p2398, 8, -1, -1, 42},
    {bmdModeHD1080p24, 8, -1, -1, 42},
    {bmdModeHD1080p25, 8, -1, -1, 42},
    {bmdModeHD1080p2997, 8, -1, -1, 42},
    {bmdModeHD1080p30, 8, -1, -1, 42},
    {bmdModeHD1080i50, 8, 20, 570, 585},
    {bmdModeHD1080i5994, 8, 20, 570, 585},
    {bmdModeHD1080i6000, 8, 20, 570, 585},
    {bmdModeHD1080p50, 8, -1, -1, 42},
    {bmdModeHD1080p5994, 8, -1, -1, 42},
    {bmdModeHD1080p6000, 8, -1, -1, 42},

     /* HD 720 Modes */

    {bmdModeHD720p50, 8, -1, -1, 26},
    {bmdModeHD720p5994, 8, -1, -1, 26},
    {bmdModeHD720p60, 8, -1, -1, 26},

    /* For all other modes, for which we don't support VANC */
    {bmdModeUnknown, 0, -1, -1, -1}
};

class decklink_allocator : public IDeckLinkMemoryAllocator
{
public:
        decklink_allocator(): _refs(1) { }
        virtual ~decklink_allocator() { }

        // IDeckLinkMemoryAllocator methods
        virtual HRESULT STDMETHODCALLTYPE AllocateBuffer(unsigned int bufferSize, void* *allocatedBuffer)
        {
            void *buf = av_malloc(bufferSize + AV_INPUT_BUFFER_PADDING_SIZE);
            if (!buf)
                return E_OUTOFMEMORY;
            *allocatedBuffer = buf;
            return S_OK;
        }
        virtual HRESULT STDMETHODCALLTYPE ReleaseBuffer(void* buffer)
        {
            av_free(buffer);
            return S_OK;
        }
        virtual HRESULT STDMETHODCALLTYPE Commit() { return S_OK; }
        virtual HRESULT STDMETHODCALLTYPE Decommit() { return S_OK; }

        // IUnknown methods
        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)
                delete this;
            return ret;
        }

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

extern "C" {
static void decklink_object_free(void *opaque, uint8_t *data)
{
    IUnknown *obj = (class IUnknown *)opaque;
    obj->Release();
}
}

static int get_vanc_line_idx(BMDDisplayMode mode)
{
    unsigned int i;
    for (i = 0; i < FF_ARRAY_ELEMS(vanc_line_numbers); i++) {
        if (mode == vanc_line_numbers[i].mode)
            return i;
    }
    /* Return the VANC idx for Unknown mode */
    return i - 1;
}

static inline void clear_parity_bits(uint16_t *buf, int len) {
    int i;
    for (i = 0; i < len; i++)
        buf[i] &= 0xff;
}

static int check_vanc_parity_checksum(uint16_t *buf, int len, uint16_t checksum) {
    int i;
    uint16_t vanc_sum = 0;
    for (i = 3; i < len - 1; i++) {
        uint16_t v = buf[i];
        int np = v >> 8;
        int p = av_parity(v & 0xff);
        if ((!!p ^ !!(v & 0x100)) || (np != 1 && np != 2)) {
            // Parity check failed
            return -1;
        }
        vanc_sum += v;
    }
    vanc_sum &= 0x1ff;
    vanc_sum |= ((~vanc_sum & 0x100) << 1);
    if (checksum != vanc_sum) {
        // Checksum verification failed
        return -1;
    }
    return 0;
}

/* The 10-bit VANC data is packed in V210, we only need the luma component. */
static void extract_luma_from_v210(uint16_t *dst, const uint8_t *src, int width)
{
    int i;
    for (i = 0; i < width / 3; i++) {
        *dst++ = (src[1] >> 2) + ((src[2] & 15) << 6);
        *dst++ =  src[4]       + ((src[5] &  3) << 8);
        *dst++ = (src[6] >> 4) + ((src[7] & 63) << 4);
        src += 8;
    }
}