PeerStreamer

/*

 * VFW capture interface

 * Copyright (c) 2006-2008 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 "libavformat/avformat.h"

#include <windows.h>

#include <vfw.h>

//#define DEBUG_VFW

/* Defines for VFW missing from MinGW.

 * Remove this when MinGW incorporates them. */

#define HWND_MESSAGE                ((HWND)-3)

#define BI_RGB                      0

/* End of missing MinGW defines */

struct vfw_ctx {

    HWND hwnd;

    HANDLE mutex;

    HANDLE event;

    AVPacketList *pktl;

    unsigned int curbufsize;

    unsigned int frame_num;

};

static enum PixelFormat vfw_pixfmt(DWORD biCompression, WORD biBitCount)

{

    switch(biCompression) {

    case MKTAG('U', 'Y', 'V', 'Y'):

        return PIX_FMT_UYVY422;

    case MKTAG('Y', 'U', 'Y', '2'):

        return PIX_FMT_YUYV422;

    case MKTAG('I', '4', '2', '0'):

        return PIX_FMT_YUV420P;

    case BI_RGB:

        switch(biBitCount) { /* 1-8 are untested */

            case 1:

                return PIX_FMT_MONOWHITE;

            case 4:

                return PIX_FMT_RGB4;

            case 8:

                return PIX_FMT_RGB8;

            case 16:

                return PIX_FMT_RGB555;

            case 24:

                return PIX_FMT_BGR24;

            case 32:

                return PIX_FMT_RGB32;

        }

    }

    return PIX_FMT_NONE;

}

static enum CodecID vfw_codecid(DWORD biCompression)

{

    switch(biCompression) {

    case MKTAG('d', 'v', 's', 'd'):

        return CODEC_ID_DVVIDEO;

    case MKTAG('M', 'J', 'P', 'G'):

    case MKTAG('m', 'j', 'p', 'g'):

        return CODEC_ID_MJPEG;

    }

    return CODEC_ID_NONE;

}

#define dstruct(pctx, sname, var, type) \

    av_log(pctx, AV_LOG_DEBUG, #var":\t%"type"\n", sname->var)

static void dump_captureparms(AVFormatContext *s, CAPTUREPARMS *cparms)

{

    av_log(s, AV_LOG_DEBUG, "CAPTUREPARMS\n");

    dstruct(s, cparms, dwRequestMicroSecPerFrame, "lu");

    dstruct(s, cparms, fMakeUserHitOKToCapture, "d");

    dstruct(s, cparms, wPercentDropForError, "u");

    dstruct(s, cparms, fYield, "d");

    dstruct(s, cparms, dwIndexSize, "lu");

    dstruct(s, cparms, wChunkGranularity, "u");

    dstruct(s, cparms, fUsingDOSMemory, "d");

    dstruct(s, cparms, wNumVideoRequested, "u");

    dstruct(s, cparms, fCaptureAudio, "d");

    dstruct(s, cparms, wNumAudioRequested, "u");

    dstruct(s, cparms, vKeyAbort, "u");

    dstruct(s, cparms, fAbortLeftMouse, "d");

    dstruct(s, cparms, fAbortRightMouse, "d");

    dstruct(s, cparms, fLimitEnabled, "d");

    dstruct(s, cparms, wTimeLimit, "u");

    dstruct(s, cparms, fMCIControl, "d");

    dstruct(s, cparms, fStepMCIDevice, "d");

    dstruct(s, cparms, dwMCIStartTime, "lu");

    dstruct(s, cparms, dwMCIStopTime, "lu");

    dstruct(s, cparms, fStepCaptureAt2x, "d");

    dstruct(s, cparms, wStepCaptureAverageFrames, "u");

    dstruct(s, cparms, dwAudioBufferSize, "lu");

    dstruct(s, cparms, fDisableWriteCache, "d");

    dstruct(s, cparms, AVStreamMaster, "u");

}

static void dump_videohdr(AVFormatContext *s, VIDEOHDR *vhdr)

{

#ifdef DEBUG_VFW

    av_log(s, AV_LOG_DEBUG, "VIDEOHDR\n");

    dstruct(s, vhdr, lpData, "p");

    dstruct(s, vhdr, dwBufferLength, "lu");

    dstruct(s, vhdr, dwBytesUsed, "lu");

    dstruct(s, vhdr, dwTimeCaptured, "lu");

    dstruct(s, vhdr, dwUser, "lu");

    dstruct(s, vhdr, dwFlags, "lu");

    dstruct(s, vhdr, dwReserved[0], "lu");

    dstruct(s, vhdr, dwReserved[1], "lu");

    dstruct(s, vhdr, dwReserved[2], "lu");

    dstruct(s, vhdr, dwReserved[3], "lu");

#endif

}

static void dump_bih(AVFormatContext *s, BITMAPINFOHEADER *bih)

{

    av_log(s, AV_LOG_DEBUG, "BITMAPINFOHEADER\n");

    dstruct(s, bih, biSize, "lu");

    dstruct(s, bih, biWidth, "ld");

    dstruct(s, bih, biHeight, "ld");

    dstruct(s, bih, biPlanes, "d");

    dstruct(s, bih, biBitCount, "d");

    dstruct(s, bih, biCompression, "lu");

    av_log(s, AV_LOG_DEBUG, "    biCompression:\t\"%.4s\"\n",

                   (char*) &bih->biCompression);

    dstruct(s, bih, biSizeImage, "lu");

    dstruct(s, bih, biXPelsPerMeter, "lu");

    dstruct(s, bih, biYPelsPerMeter, "lu");

    dstruct(s, bih, biClrUsed, "lu");

    dstruct(s, bih, biClrImportant, "lu");

}

static int shall_we_drop(AVFormatContext *s)

{

    struct vfw_ctx *ctx = s->priv_data;

    const uint8_t dropscore[] = {62, 75, 87, 100};

    const int ndropscores = FF_ARRAY_ELEMS(dropscore);

    unsigned int buffer_fullness = (ctx->curbufsize*100)/s->max_picture_buffer;

    if(dropscore[++ctx->frame_num%ndropscores] <= buffer_fullness) {

        av_log(s, AV_LOG_ERROR,

              "real-time buffer %d%% full! frame dropped!\n", buffer_fullness);

        return 1;

    }

    return 0;

}

static LRESULT CALLBACK videostream_cb(HWND hwnd, LPVIDEOHDR vdhdr)

{

    AVFormatContext *s;

    struct vfw_ctx *ctx;

    AVPacketList **ppktl, *pktl_next;

    s = (AVFormatContext *) GetWindowLongPtr(hwnd, GWLP_USERDATA);

    ctx = s->priv_data;

    dump_videohdr(s, vdhdr);

    if(shall_we_drop(s))

        return FALSE;

    WaitForSingleObject(ctx->mutex, INFINITE);

    pktl_next = av_mallocz(sizeof(AVPacketList));

    if(!pktl_next)

        goto fail;

    if(av_new_packet(&pktl_next->pkt, vdhdr->dwBytesUsed) < 0) {

        av_free(pktl_next);

        goto fail;

    }

    pktl_next->pkt.pts = vdhdr->dwTimeCaptured;

    memcpy(pktl_next->pkt.data, vdhdr->lpData, vdhdr->dwBytesUsed);

    for(ppktl = &ctx->pktl ; *ppktl ; ppktl = &(*ppktl)->next);

    *ppktl = pktl_next;

    ctx->curbufsize += vdhdr->dwBytesUsed;

    SetEvent(ctx->event);

    ReleaseMutex(ctx->mutex);

    return TRUE;

fail:

    ReleaseMutex(ctx->mutex);

    return FALSE;

}

static int vfw_read_close(AVFormatContext *s)

{

    struct vfw_ctx *ctx = s->priv_data;

    AVPacketList *pktl;

    if(ctx->hwnd) {

        SendMessage(ctx->hwnd, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0, 0);

        SendMessage(ctx->hwnd, WM_CAP_DRIVER_DISCONNECT, 0, 0);

        DestroyWindow(ctx->hwnd);

    }

    if(ctx->mutex)

        CloseHandle(ctx->mutex);

    if(ctx->event)

        CloseHandle(ctx->event);

    pktl = ctx->pktl;

    while (pktl) {

        AVPacketList *next = pktl->next;

        av_destruct_packet(&pktl->pkt);

        av_free(pktl);

        pktl = next;

    }

    return 0;

}

static int vfw_read_header(AVFormatContext *s, AVFormatParameters *ap)

{

    struct vfw_ctx *ctx = s->priv_data;

    AVCodecContext *codec;

    AVStream *st;

    int devnum;

    int bisize;

    BITMAPINFO *bi;

    CAPTUREPARMS cparms;

    DWORD biCompression;

    WORD biBitCount;

    int width;

    int height;

    int ret;

    if(!ap->time_base.den) {

        av_log(s, AV_LOG_ERROR, "A time base must be specified.\n");

        return AVERROR(EIO);

    }

    ctx->hwnd = capCreateCaptureWindow(NULL, 0, 0, 0, 0, 0, HWND_MESSAGE, 0);

    if(!ctx->hwnd) {

        av_log(s, AV_LOG_ERROR, "Could not create capture window.\n");

        return AVERROR(EIO);

    }

    /* If atoi fails, devnum==0 and the default device is used */

    devnum = atoi(s->filename);

    ret = SendMessage(ctx->hwnd, WM_CAP_DRIVER_CONNECT, devnum, 0);

    if(!ret) {

        av_log(s, AV_LOG_ERROR, "Could not connect to device.\n");

        DestroyWindow(ctx->hwnd);

        return AVERROR(ENODEV);

    }

    SendMessage(ctx->hwnd, WM_CAP_SET_OVERLAY, 0, 0);

    SendMessage(ctx->hwnd, WM_CAP_SET_PREVIEW, 0, 0);

    ret = SendMessage(ctx->hwnd, WM_CAP_SET_CALLBACK_VIDEOSTREAM, 0,

                      (LPARAM) videostream_cb);

    if(!ret) {

        av_log(s, AV_LOG_ERROR, "Could not set video stream callback.\n");

        goto fail_io;

    }

    SetWindowLongPtr(ctx->hwnd, GWLP_USERDATA, (LONG_PTR) s);

    st = av_new_stream(s, 0);

    if(!st) {

        vfw_read_close(s);

        return AVERROR(ENOMEM);

    }

    /* Set video format */

    bisize = SendMessage(ctx->hwnd, WM_CAP_GET_VIDEOFORMAT, 0, 0);

    if(!bisize)

        goto fail_io;

    bi = av_malloc(bisize);

    if(!bi) {

        vfw_read_close(s);

        return AVERROR(ENOMEM);

    }

    ret = SendMessage(ctx->hwnd, WM_CAP_GET_VIDEOFORMAT, bisize, (LPARAM) bi);

    if(!ret)

        goto fail_bi;

    dump_bih(s, &bi->bmiHeader);

    width  = ap->width  ? ap->width  : bi->bmiHeader.biWidth ;

    height = ap->height ? ap->height : bi->bmiHeader.biHeight;

    bi->bmiHeader.biWidth  = width ;

    bi->bmiHeader.biHeight = height;

    if (0) {

        /* For testing yet unsupported compressions

         * Copy these values from user-supplied verbose information */

        bi->bmiHeader.biWidth       = 320;

        bi->bmiHeader.biHeight      = 240;

        bi->bmiHeader.biPlanes      = 1;

        bi->bmiHeader.biBitCount    = 12;

        bi->bmiHeader.biCompression = MKTAG('I','4','2','0');

        bi->bmiHeader.biSizeImage   = 115200;

        dump_bih(s, &bi->bmiHeader);

    }

    ret = SendMessage(ctx->hwnd, WM_CAP_SET_VIDEOFORMAT, bisize, (LPARAM) bi);

    if(!ret) {

        av_log(s, AV_LOG_ERROR, "Could not set Video Format.\n");

        goto fail_bi;

    }

    biCompression = bi->bmiHeader.biCompression;

    biBitCount = bi->bmiHeader.biBitCount;

    av_free(bi);

    /* Set sequence setup */

    ret = SendMessage(ctx->hwnd, WM_CAP_GET_SEQUENCE_SETUP, sizeof(cparms),

                      (LPARAM) &cparms);

    if(!ret)

        goto fail_io;

    dump_captureparms(s, &cparms);

    cparms.fYield = 1; // Spawn a background thread

    cparms.dwRequestMicroSecPerFrame =

                               (ap->time_base.num*1000000) / ap->time_base.den;

    cparms.fAbortLeftMouse = 0;

    cparms.fAbortRightMouse = 0;

    cparms.fCaptureAudio = 0;

    cparms.vKeyAbort = 0;

    ret = SendMessage(ctx->hwnd, WM_CAP_SET_SEQUENCE_SETUP, sizeof(cparms),

                      (LPARAM) &cparms);

    if(!ret)

        goto fail_io;

    codec = st->codec;

    codec->time_base = ap->time_base;

    codec->codec_type = AVMEDIA_TYPE_VIDEO;

    codec->width = width;

    codec->height = height;

    codec->pix_fmt = vfw_pixfmt(biCompression, biBitCount);

    if(codec->pix_fmt == PIX_FMT_NONE) {

        codec->codec_id = vfw_codecid(biCompression);

        if(codec->codec_id == CODEC_ID_NONE) {

            av_log(s, AV_LOG_ERROR, "Unknown compression type. "

                             "Please report verbose (-v 9) debug information.\n");

            vfw_read_close(s);

            return AVERROR_PATCHWELCOME;

        }

        codec->bits_per_coded_sample = biBitCount;

    } else {

        codec->codec_id = CODEC_ID_RAWVIDEO;

        if(biCompression == BI_RGB)

            codec->bits_per_coded_sample = biBitCount;

    }

    av_set_pts_info(st, 32, 1, 1000);

    ctx->mutex = CreateMutex(NULL, 0, NULL);

    if(!ctx->mutex) {

        av_log(s, AV_LOG_ERROR, "Could not create Mutex.\n" );

        goto fail_io;

    }

    ctx->event = CreateEvent(NULL, 1, 0, NULL);

    if(!ctx->event) {

        av_log(s, AV_LOG_ERROR, "Could not create Event.\n" );

        goto fail_io;

    }

    ret = SendMessage(ctx->hwnd, WM_CAP_SEQUENCE_NOFILE, 0, 0);

    if(!ret) {

        av_log(s, AV_LOG_ERROR, "Could not start capture sequence.\n" );

        goto fail_io;

    }

    return 0;

fail_bi:

    av_free(bi);

fail_io:

    vfw_read_close(s);

    return AVERROR(EIO);

}

static int vfw_read_packet(AVFormatContext *s, AVPacket *pkt)

{

    struct vfw_ctx *ctx = s->priv_data;

    AVPacketList *pktl = NULL;

    while(!pktl) {

        WaitForSingleObject(ctx->mutex, INFINITE);

        pktl = ctx->pktl;

        if(ctx->pktl) {

            *pkt = ctx->pktl->pkt;

            ctx->pktl = ctx->pktl->next;

            av_free(pktl);

        }

        ResetEvent(ctx->event);

        ReleaseMutex(ctx->mutex);

        if(!pktl) {

            if(s->flags & AVFMT_FLAG_NONBLOCK) {

                return AVERROR(EAGAIN);

            } else {

                WaitForSingleObject(ctx->event, INFINITE);

            }

        }

    }

    ctx->curbufsize -= pkt->size;

    return pkt->size;

}

AVInputFormat vfwcap_demuxer = {

    "vfwcap",

    NULL_IF_CONFIG_SMALL("VFW video capture"),

    sizeof(struct vfw_ctx),

    NULL,

    vfw_read_header,

    vfw_read_packet,

    vfw_read_close,

    .flags = AVFMT_NOFILE,

};