/*
  * Directshow capture interface
  * Copyright (c) 2010 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 "libavutil/parseutils.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/opt.h"

 #include "libavformat/internal.h"

 #include "libavformat/riff.h"

 #include "avdevice.h"

 #include "dshow_capture.h"

 #include "libavcodec/raw.h"

 
 struct dshow_ctx {

     const AVClass *class;
 

     IGraphBuilder *graph;
 
     char *device_name[2];

     int video_device_number;
     int audio_device_number;

     int   list_options;

     int   list_devices;

     int   audio_buffer_size;

     IBaseFilter *device_filter[2];
     IPin        *device_pin[2];
     libAVFilter *capture_filter[2];
     libAVPin    *capture_pin[2];
 
     HANDLE mutex;

     HANDLE event[2]; /* event[0] is set by DirectShow
                       * event[1] is set by callback() */

     AVPacketList *pktl;
 

     int eof;
 

     int64_t curbufsize[2];

     unsigned int video_frame_num;
 
     IMediaControl *control;

     IMediaEvent *media_event;

     enum AVPixelFormat pixel_format;

     enum AVCodecID video_codec_id;

     char *framerate;
 
     int requested_width;
     int requested_height;
     AVRational requested_framerate;
 
     int sample_rate;
     int sample_size;
     int channels;

 };
 

 static enum AVPixelFormat dshow_pixfmt(DWORD biCompression, WORD biBitCount)

 {
     switch(biCompression) {

     case BI_BITFIELDS:

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

                 return AV_PIX_FMT_MONOWHITE;

             case 4:

                 return AV_PIX_FMT_RGB4;

             case 8:

                 return AV_PIX_FMT_RGB8;

             case 16:

                 return AV_PIX_FMT_RGB555;

             case 24:

                 return AV_PIX_FMT_BGR24;

             case 32:

                 return AV_PIX_FMT_0RGB32;

         }
     }

     return avpriv_find_pix_fmt(avpriv_get_raw_pix_fmt_tags(), biCompression); // all others

 }
 
 static int
 dshow_read_close(AVFormatContext *s)
 {
     struct dshow_ctx *ctx = s->priv_data;
     AVPacketList *pktl;
 
     if (ctx->control) {
         IMediaControl_Stop(ctx->control);
         IMediaControl_Release(ctx->control);
     }
 

     if (ctx->media_event)
         IMediaEvent_Release(ctx->media_event);
 

     if (ctx->graph) {
         IEnumFilters *fenum;
         int r;
         r = IGraphBuilder_EnumFilters(ctx->graph, &fenum);
         if (r == S_OK) {
             IBaseFilter *f;
             IEnumFilters_Reset(fenum);

             while (IEnumFilters_Next(fenum, 1, &f, NULL) == S_OK) {

                 if (IGraphBuilder_RemoveFilter(ctx->graph, f) == S_OK)
                     IEnumFilters_Reset(fenum); /* When a filter is removed,
                                                 * the list must be reset. */

                 IBaseFilter_Release(f);
             }

             IEnumFilters_Release(fenum);
         }
         IGraphBuilder_Release(ctx->graph);
     }
 

     if (ctx->capture_pin[VideoDevice])
         libAVPin_Release(ctx->capture_pin[VideoDevice]);
     if (ctx->capture_pin[AudioDevice])
         libAVPin_Release(ctx->capture_pin[AudioDevice]);
     if (ctx->capture_filter[VideoDevice])
         libAVFilter_Release(ctx->capture_filter[VideoDevice]);
     if (ctx->capture_filter[AudioDevice])
         libAVFilter_Release(ctx->capture_filter[AudioDevice]);
 
     if (ctx->device_pin[VideoDevice])
         IPin_Release(ctx->device_pin[VideoDevice]);
     if (ctx->device_pin[AudioDevice])
         IPin_Release(ctx->device_pin[AudioDevice]);
     if (ctx->device_filter[VideoDevice])
         IBaseFilter_Release(ctx->device_filter[VideoDevice]);
     if (ctx->device_filter[AudioDevice])
         IBaseFilter_Release(ctx->device_filter[AudioDevice]);
 
     if (ctx->device_name[0])
         av_free(ctx->device_name[0]);
     if (ctx->device_name[1])
         av_free(ctx->device_name[1]);
 
     if(ctx->mutex)
         CloseHandle(ctx->mutex);

     if(ctx->event[0])
         CloseHandle(ctx->event[0]);
     if(ctx->event[1])
         CloseHandle(ctx->event[1]);

 
     pktl = ctx->pktl;
     while (pktl) {
         AVPacketList *next = pktl->next;
         av_destruct_packet(&pktl->pkt);
         av_free(pktl);
         pktl = next;
     }
 

     CoUninitialize();
 

     return 0;
 }
 
 static char *dup_wchar_to_utf8(wchar_t *w)
 {
     char *s = NULL;
     int l = WideCharToMultiByte(CP_UTF8, 0, w, -1, 0, 0, 0, 0);
     s = av_malloc(l);
     if (s)
         WideCharToMultiByte(CP_UTF8, 0, w, -1, s, l, 0, 0);
     return s;
 }
 

 static int shall_we_drop(AVFormatContext *s, int index, enum dshowDeviceType devtype)

 {
     struct dshow_ctx *ctx = s->priv_data;

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

     const int ndropscores = FF_ARRAY_ELEMS(dropscore);

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

 
     if(dropscore[++ctx->video_frame_num%ndropscores] <= buffer_fullness) {
         av_log(s, AV_LOG_ERROR,

               "real-time buffer[%s] too full (%d%% of size: %d)! frame dropped!\n", ctx->device_name[devtype], buffer_fullness, s->max_picture_buffer);

         return 1;
     }
 
     return 0;
 }
 
 static void

 callback(void *priv_data, int index, uint8_t *buf, int buf_size, int64_t time, enum dshowDeviceType devtype)

 {
     AVFormatContext *s = priv_data;
     struct dshow_ctx *ctx = s->priv_data;
     AVPacketList **ppktl, *pktl_next;
 
 //    dump_videohdr(s, vdhdr);
 
     WaitForSingleObject(ctx->mutex, INFINITE);
 

     if(shall_we_drop(s, index, devtype))

         goto fail;
 

     pktl_next = av_mallocz(sizeof(AVPacketList));
     if(!pktl_next)
         goto fail;
 
     if(av_new_packet(&pktl_next->pkt, buf_size) < 0) {
         av_free(pktl_next);
         goto fail;
     }
 
     pktl_next->pkt.stream_index = index;
     pktl_next->pkt.pts = time;
     memcpy(pktl_next->pkt.data, buf, buf_size);
 
     for(ppktl = &ctx->pktl ; *ppktl ; ppktl = &(*ppktl)->next);
     *ppktl = pktl_next;

     ctx->curbufsize[index] += buf_size;

     SetEvent(ctx->event[1]);

     ReleaseMutex(ctx->mutex);
 
     return;
 fail:
     ReleaseMutex(ctx->mutex);
     return;
 }
 

 /**
  * Cycle through available devices using the device enumerator devenum,
  * retrieve the device with type specified by devtype and return the
  * pointer to the object found in *pfilter.

  * If pfilter is NULL, list all device names.

  */

 static int

 dshow_cycle_devices(AVFormatContext *avctx, ICreateDevEnum *devenum,
                     enum dshowDeviceType devtype, IBaseFilter **pfilter)

 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IBaseFilter *device_filter = NULL;
     IEnumMoniker *classenum = NULL;
     IMoniker *m = NULL;
     const char *device_name = ctx->device_name[devtype];

     int skip = (devtype == VideoDevice) ? ctx->video_device_number
                                         : ctx->audio_device_number;

     int r;

 
     const GUID *device_guid[2] = { &CLSID_VideoInputDeviceCategory,
                                    &CLSID_AudioInputDeviceCategory };
     const char *devtypename = (devtype == VideoDevice) ? "video" : "audio";
 
     r = ICreateDevEnum_CreateClassEnumerator(devenum, device_guid[devtype],
                                              (IEnumMoniker **) &classenum, 0);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not enumerate %s devices.\n",
                devtypename);

         return AVERROR(EIO);

     }
 

     while (!device_filter && IEnumMoniker_Next(classenum, 1, &m, NULL) == S_OK) {

         IPropertyBag *bag = NULL;
         char *buf = NULL;
         VARIANT var;
 
         r = IMoniker_BindToStorage(m, 0, 0, &IID_IPropertyBag, (void *) &bag);
         if (r != S_OK)
             goto fail1;
 
         var.vt = VT_BSTR;
         r = IPropertyBag_Read(bag, L"FriendlyName", &var, NULL);
         if (r != S_OK)
             goto fail1;
 
         buf = dup_wchar_to_utf8(var.bstrVal);
 

         if (pfilter) {

             if (strcmp(device_name, buf))
                 goto fail1;

             if (!skip--)

                 IMoniker_BindToObject(m, 0, 0, &IID_IBaseFilter, (void *) &device_filter);

         } else {
             av_log(avctx, AV_LOG_INFO, " \"%s\"\n", buf);
         }

 
 fail1:
         if (buf)
             av_free(buf);
         if (bag)
             IPropertyBag_Release(bag);
         IMoniker_Release(m);
     }
 

     IEnumMoniker_Release(classenum);
 

     if (pfilter) {

         if (!device_filter) {
             av_log(avctx, AV_LOG_ERROR, "Could not find %s device.\n",
                    devtypename);
             return AVERROR(EIO);
         }
         *pfilter = device_filter;

     }

 
     return 0;
 }
 

 /**

  * Cycle through available formats using the specified pin,
  * try to set parameters specified through AVOptions and if successful
  * return 1 in *pformat_set.

  * If pformat_set is NULL, list all pin capabilities.

  */
 static void
 dshow_cycle_formats(AVFormatContext *avctx, enum dshowDeviceType devtype,
                     IPin *pin, int *pformat_set)
 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IAMStreamConfig *config = NULL;
     AM_MEDIA_TYPE *type = NULL;
     int format_set = 0;
     void *caps = NULL;
     int i, n, size;
 
     if (IPin_QueryInterface(pin, &IID_IAMStreamConfig, (void **) &config) != S_OK)
         return;
     if (IAMStreamConfig_GetNumberOfCapabilities(config, &n, &size) != S_OK)
         goto end;
 
     caps = av_malloc(size);
     if (!caps)
         goto end;
 
     for (i = 0; i < n && !format_set; i++) {
         IAMStreamConfig_GetStreamCaps(config, i, &type, (void *) caps);
 
 #if DSHOWDEBUG
         ff_print_AM_MEDIA_TYPE(type);
 #endif
 
         if (devtype == VideoDevice) {
             VIDEO_STREAM_CONFIG_CAPS *vcaps = caps;
             BITMAPINFOHEADER *bih;
             int64_t *fr;

             const AVCodecTag *const tags[] = { avformat_get_riff_video_tags(), NULL };

 #if DSHOWDEBUG
             ff_print_VIDEO_STREAM_CONFIG_CAPS(vcaps);
 #endif
             if (IsEqualGUID(&type->formattype, &FORMAT_VideoInfo)) {
                 VIDEOINFOHEADER *v = (void *) type->pbFormat;
                 fr = &v->AvgTimePerFrame;
                 bih = &v->bmiHeader;
             } else if (IsEqualGUID(&type->formattype, &FORMAT_VideoInfo2)) {
                 VIDEOINFOHEADER2 *v = (void *) type->pbFormat;
                 fr = &v->AvgTimePerFrame;
                 bih = &v->bmiHeader;
             } else {
                 goto next;
             }

             if (!pformat_set) {

                 enum AVPixelFormat pix_fmt = dshow_pixfmt(bih->biCompression, bih->biBitCount);
                 if (pix_fmt == AV_PIX_FMT_NONE) {

                     enum AVCodecID codec_id = av_codec_get_id(tags, bih->biCompression);

                     AVCodec *codec = avcodec_find_decoder(codec_id);
                     if (codec_id == AV_CODEC_ID_NONE || !codec) {

                         av_log(avctx, AV_LOG_INFO, "  unknown compression type 0x%X", (int) bih->biCompression);

                     } else {
                         av_log(avctx, AV_LOG_INFO, "  vcodec=%s", codec->name);
                     }
                 } else {
                     av_log(avctx, AV_LOG_INFO, "  pixel_format=%s", av_get_pix_fmt_name(pix_fmt));
                 }

                 av_log(avctx, AV_LOG_INFO, "  min s=%ldx%ld fps=%g max s=%ldx%ld fps=%g\n",
                        vcaps->MinOutputSize.cx, vcaps->MinOutputSize.cy,

                        1e7 / vcaps->MaxFrameInterval,

                        vcaps->MaxOutputSize.cx, vcaps->MaxOutputSize.cy,

                        1e7 / vcaps->MinFrameInterval);

                 continue;
             }

             if (ctx->video_codec_id != AV_CODEC_ID_RAWVIDEO) {

                 if (ctx->video_codec_id != av_codec_get_id(tags, bih->biCompression))

                     goto next;
             }

             if (ctx->pixel_format != AV_PIX_FMT_NONE &&

                 ctx->pixel_format != dshow_pixfmt(bih->biCompression, bih->biBitCount)) {
                 goto next;
             }

             if (ctx->framerate) {
                 int64_t framerate = ((int64_t) ctx->requested_framerate.den*10000000)
                                             /  ctx->requested_framerate.num;
                 if (framerate > vcaps->MaxFrameInterval ||
                     framerate < vcaps->MinFrameInterval)
                     goto next;
                 *fr = framerate;
             }

             if (ctx->requested_width && ctx->requested_height) {

                 if (ctx->requested_width  > vcaps->MaxOutputSize.cx ||
                     ctx->requested_width  < vcaps->MinOutputSize.cx ||
                     ctx->requested_height > vcaps->MaxOutputSize.cy ||
                     ctx->requested_height < vcaps->MinOutputSize.cy)
                     goto next;
                 bih->biWidth  = ctx->requested_width;
                 bih->biHeight = ctx->requested_height;
             }
         } else {
             AUDIO_STREAM_CONFIG_CAPS *acaps = caps;
             WAVEFORMATEX *fx;
 #if DSHOWDEBUG
             ff_print_AUDIO_STREAM_CONFIG_CAPS(acaps);
 #endif
             if (IsEqualGUID(&type->formattype, &FORMAT_WaveFormatEx)) {
                 fx = (void *) type->pbFormat;
             } else {
                 goto next;
             }

             if (!pformat_set) {
                 av_log(avctx, AV_LOG_INFO, "  min ch=%lu bits=%lu rate=%6lu max ch=%lu bits=%lu rate=%6lu\n",
                        acaps->MinimumChannels, acaps->MinimumBitsPerSample, acaps->MinimumSampleFrequency,
                        acaps->MaximumChannels, acaps->MaximumBitsPerSample, acaps->MaximumSampleFrequency);
                 continue;
             }

             if (ctx->sample_rate) {
                 if (ctx->sample_rate > acaps->MaximumSampleFrequency ||
                     ctx->sample_rate < acaps->MinimumSampleFrequency)
                     goto next;
                 fx->nSamplesPerSec = ctx->sample_rate;
             }
             if (ctx->sample_size) {
                 if (ctx->sample_size > acaps->MaximumBitsPerSample ||
                     ctx->sample_size < acaps->MinimumBitsPerSample)
                     goto next;
                 fx->wBitsPerSample = ctx->sample_size;
             }
             if (ctx->channels) {
                 if (ctx->channels > acaps->MaximumChannels ||
                     ctx->channels < acaps->MinimumChannels)
                     goto next;
                 fx->nChannels = ctx->channels;
             }
         }
         if (IAMStreamConfig_SetFormat(config, type) != S_OK)
             goto next;
         format_set = 1;
 next:
         if (type->pbFormat)
             CoTaskMemFree(type->pbFormat);
         CoTaskMemFree(type);
     }
 end:
     IAMStreamConfig_Release(config);
     if (caps)
         av_free(caps);

     if (pformat_set)

         *pformat_set = format_set;

 }
 
 /**

  * Set audio device buffer size in milliseconds (which can directly impact
  * latency, depending on the device).
  */
 static int
 dshow_set_audio_buffer_size(AVFormatContext *avctx, IPin *pin)
 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IAMBufferNegotiation *buffer_negotiation = NULL;
     ALLOCATOR_PROPERTIES props = { -1, -1, -1, -1 };
     IAMStreamConfig *config = NULL;
     AM_MEDIA_TYPE *type = NULL;
     int ret = AVERROR(EIO);
 
     if (IPin_QueryInterface(pin, &IID_IAMStreamConfig, (void **) &config) != S_OK)
         goto end;
     if (IAMStreamConfig_GetFormat(config, &type) != S_OK)
         goto end;
     if (!IsEqualGUID(&type->formattype, &FORMAT_WaveFormatEx))
         goto end;
 
     props.cbBuffer = (((WAVEFORMATEX *) type->pbFormat)->nAvgBytesPerSec)
                    * ctx->audio_buffer_size / 1000;
 
     if (IPin_QueryInterface(pin, &IID_IAMBufferNegotiation, (void **) &buffer_negotiation) != S_OK)
         goto end;
     if (IAMBufferNegotiation_SuggestAllocatorProperties(buffer_negotiation, &props) != S_OK)
         goto end;
 
     ret = 0;
 
 end:
     if (buffer_negotiation)
         IAMBufferNegotiation_Release(buffer_negotiation);
     if (type) {
         if (type->pbFormat)
             CoTaskMemFree(type->pbFormat);
         CoTaskMemFree(type);
     }
     if (config)
         IAMStreamConfig_Release(config);
 
     return ret;
 }
 
 /**

  * Cycle through available pins using the device_filter device, of type
  * devtype, retrieve the first output pin and return the pointer to the
  * object found in *ppin.

  * If ppin is NULL, cycle through all pins listing audio/video capabilities.

  */

 static int

 dshow_cycle_pins(AVFormatContext *avctx, enum dshowDeviceType devtype,
                  IBaseFilter *device_filter, IPin **ppin)

 {

     struct dshow_ctx *ctx = avctx->priv_data;

     IEnumPins *pins = 0;
     IPin *device_pin = NULL;
     IPin *pin;
     int r;
 
     const GUID *mediatype[2] = { &MEDIATYPE_Video, &MEDIATYPE_Audio };
     const char *devtypename = (devtype == VideoDevice) ? "video" : "audio";

     int set_format = (devtype == VideoDevice && (ctx->framerate ||
                                                 (ctx->requested_width && ctx->requested_height) ||

                                                  ctx->pixel_format != AV_PIX_FMT_NONE ||

                                                  ctx->video_codec_id != AV_CODEC_ID_RAWVIDEO))

                   || (devtype == AudioDevice && (ctx->channels || ctx->sample_rate));
     int format_set = 0;
 

     r = IBaseFilter_EnumPins(device_filter, &pins);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not enumerate pins.\n");

         return AVERROR(EIO);

     }
 

     if (!ppin) {
         av_log(avctx, AV_LOG_INFO, "DirectShow %s device options\n",
                devtypename);
     }

     while (!device_pin && IEnumPins_Next(pins, 1, &pin, NULL) == S_OK) {

         IKsPropertySet *p = NULL;

         IEnumMediaTypes *types = NULL;

         PIN_INFO info = {0};
         AM_MEDIA_TYPE *type;
         GUID category;
         DWORD r2;
 
         IPin_QueryPinInfo(pin, &info);
         IBaseFilter_Release(info.pFilter);
 
         if (info.dir != PINDIR_OUTPUT)
             goto next;
         if (IPin_QueryInterface(pin, &IID_IKsPropertySet, (void **) &p) != S_OK)
             goto next;
         if (IKsPropertySet_Get(p, &AMPROPSETID_Pin, AMPROPERTY_PIN_CATEGORY,
                                NULL, 0, &category, sizeof(GUID), &r2) != S_OK)
             goto next;
         if (!IsEqualGUID(&category, &PIN_CATEGORY_CAPTURE))
             goto next;
 

         if (!ppin) {
             char *buf = dup_wchar_to_utf8(info.achName);
             av_log(avctx, AV_LOG_INFO, " Pin \"%s\"\n", buf);
             av_free(buf);
             dshow_cycle_formats(avctx, devtype, pin, NULL);
             goto next;
         }

         if (set_format) {
             dshow_cycle_formats(avctx, devtype, pin, &format_set);
             if (!format_set) {
                 goto next;
             }
         }

         if (devtype == AudioDevice && ctx->audio_buffer_size) {

             if (dshow_set_audio_buffer_size(avctx, pin) < 0) {
                 av_log(avctx, AV_LOG_ERROR, "unable to set audio buffer size %d to pin, using pin anyway...", ctx->audio_buffer_size);
             }

         }

         if (IPin_EnumMediaTypes(pin, &types) != S_OK)
             goto next;
 
         IEnumMediaTypes_Reset(types);

         while (!device_pin && IEnumMediaTypes_Next(types, 1, &type, NULL) == S_OK) {

             if (IsEqualGUID(&type->majortype, mediatype[devtype])) {
                 device_pin = pin;
                 goto next;
             }
             CoTaskMemFree(type);
         }
 
 next:
         if (types)
             IEnumMediaTypes_Release(types);
         if (p)
             IKsPropertySet_Release(p);
         if (device_pin != pin)
             IPin_Release(pin);
     }
 

     IEnumPins_Release(pins);
 

     if (ppin) {

         if (set_format && !format_set) {
             av_log(avctx, AV_LOG_ERROR, "Could not set %s options\n", devtypename);
             return AVERROR(EIO);
         }
         if (!device_pin) {
             av_log(avctx, AV_LOG_ERROR,
                 "Could not find output pin from %s capture device.\n", devtypename);
             return AVERROR(EIO);
         }
         *ppin = device_pin;

     }
 
     return 0;
 }
 
 /**
  * List options for device with type devtype.
  *
  * @param devenum device enumerator used for accessing the device
  */
 static int
 dshow_list_device_options(AVFormatContext *avctx, ICreateDevEnum *devenum,
                           enum dshowDeviceType devtype)
 {

     struct dshow_ctx *ctx = avctx->priv_data;

     IBaseFilter *device_filter = NULL;
     int r;
 
     if ((r = dshow_cycle_devices(avctx, devenum, devtype, &device_filter)) < 0)
         return r;

     ctx->device_filter[devtype] = device_filter;

     if ((r = dshow_cycle_pins(avctx, devtype, device_filter, NULL)) < 0)
         return r;

 
     return 0;
 }
 
 static int
 dshow_open_device(AVFormatContext *avctx, ICreateDevEnum *devenum,
                   enum dshowDeviceType devtype)
 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IBaseFilter *device_filter = NULL;
     IGraphBuilder *graph = ctx->graph;
     IPin *device_pin = NULL;
     libAVPin *capture_pin = NULL;
     libAVFilter *capture_filter = NULL;
     int ret = AVERROR(EIO);
     int r;
 
     const wchar_t *filter_name[2] = { L"Audio capture filter", L"Video capture filter" };
 
     if ((r = dshow_cycle_devices(avctx, devenum, devtype, &device_filter)) < 0) {
         ret = r;
         goto error;
     }
 
     ctx->device_filter [devtype] = device_filter;
 
     r = IGraphBuilder_AddFilter(graph, device_filter, NULL);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not add device filter to graph.\n");
         goto error;
     }
 
     if ((r = dshow_cycle_pins(avctx, devtype, device_filter, &device_pin)) < 0) {
         ret = r;

         goto error;
     }
     ctx->device_pin[devtype] = device_pin;
 
     capture_filter = libAVFilter_Create(avctx, callback, devtype);
     if (!capture_filter) {
         av_log(avctx, AV_LOG_ERROR, "Could not create grabber filter.\n");
         goto error;
     }
     ctx->capture_filter[devtype] = capture_filter;
 
     r = IGraphBuilder_AddFilter(graph, (IBaseFilter *) capture_filter,
                                 filter_name[devtype]);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not add capture filter to graph\n");
         goto error;
     }
 
     libAVPin_AddRef(capture_filter->pin);
     capture_pin = capture_filter->pin;
     ctx->capture_pin[devtype] = capture_pin;
 
     r = IGraphBuilder_ConnectDirect(graph, device_pin, (IPin *) capture_pin, NULL);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not connect pins\n");
         goto error;
     }
 
     ret = 0;
 
 error:
     return ret;
 }
 

 static enum AVCodecID waveform_codec_id(enum AVSampleFormat sample_fmt)

 {
     switch (sample_fmt) {

     case AV_SAMPLE_FMT_U8:  return AV_CODEC_ID_PCM_U8;
     case AV_SAMPLE_FMT_S16: return AV_CODEC_ID_PCM_S16LE;
     case AV_SAMPLE_FMT_S32: return AV_CODEC_ID_PCM_S32LE;
     default:                return AV_CODEC_ID_NONE; /* Should never happen. */

     }
 }
 

 static enum AVSampleFormat sample_fmt_bits_per_sample(int bits)

 {
     switch (bits) {
     case 8:  return AV_SAMPLE_FMT_U8;
     case 16: return AV_SAMPLE_FMT_S16;
     case 32: return AV_SAMPLE_FMT_S32;
     default: return AV_SAMPLE_FMT_NONE; /* Should never happen. */
     }
 }
 
 static int

 dshow_add_device(AVFormatContext *avctx,

                  enum dshowDeviceType devtype)
 {
     struct dshow_ctx *ctx = avctx->priv_data;
     AM_MEDIA_TYPE type;
     AVCodecContext *codec;
     AVStream *st;
     int ret = AVERROR(EIO);
 

     st = avformat_new_stream(avctx, NULL);

     if (!st) {
         ret = AVERROR(ENOMEM);
         goto error;
     }

     st->id = devtype;

 
     ctx->capture_filter[devtype]->stream_index = st->index;
 
     libAVPin_ConnectionMediaType(ctx->capture_pin[devtype], &type);
 
     codec = st->codec;
     if (devtype == VideoDevice) {
         BITMAPINFOHEADER *bih = NULL;

         AVRational time_base;

 
         if (IsEqualGUID(&type.formattype, &FORMAT_VideoInfo)) {
             VIDEOINFOHEADER *v = (void *) type.pbFormat;

             time_base = (AVRational) { v->AvgTimePerFrame, 10000000 };

             bih = &v->bmiHeader;
         } else if (IsEqualGUID(&type.formattype, &FORMAT_VideoInfo2)) {
             VIDEOINFOHEADER2 *v = (void *) type.pbFormat;

             time_base = (AVRational) { v->AvgTimePerFrame, 10000000 };

             bih = &v->bmiHeader;
         }
         if (!bih) {
             av_log(avctx, AV_LOG_ERROR, "Could not get media type.\n");
             goto error;
         }
 

         codec->time_base  = time_base;

         codec->codec_type = AVMEDIA_TYPE_VIDEO;
         codec->width      = bih->biWidth;
         codec->height     = bih->biHeight;

         codec->codec_tag  = bih->biCompression;

         codec->pix_fmt    = dshow_pixfmt(bih->biCompression, bih->biBitCount);

         if (bih->biCompression == MKTAG('H', 'D', 'Y', 'C')) {
             av_log(avctx, AV_LOG_DEBUG, "attempt to use full range for HDYC...\n");
             codec->color_range = AVCOL_RANGE_MPEG; // just in case it needs this...

         }

         if (codec->pix_fmt == AV_PIX_FMT_NONE) {

             const AVCodecTag *const tags[] = { avformat_get_riff_video_tags(), NULL };
             codec->codec_id = av_codec_get_id(tags, bih->biCompression);

             if (codec->codec_id == AV_CODEC_ID_NONE) {

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

                                  "Please report type 0x%X.\n", (int) bih->biCompression);

                 return AVERROR_PATCHWELCOME;
             }
             codec->bits_per_coded_sample = bih->biBitCount;
         } else {

             codec->codec_id = AV_CODEC_ID_RAWVIDEO;

             if (bih->biCompression == BI_RGB || bih->biCompression == BI_BITFIELDS) {

                 codec->bits_per_coded_sample = bih->biBitCount;
                 codec->extradata = av_malloc(9 + FF_INPUT_BUFFER_PADDING_SIZE);
                 if (codec->extradata) {
                     codec->extradata_size = 9;
                     memcpy(codec->extradata, "BottomUp", 9);
                 }
             }
         }
     } else {
         WAVEFORMATEX *fx = NULL;
 
         if (IsEqualGUID(&type.formattype, &FORMAT_WaveFormatEx)) {
             fx = (void *) type.pbFormat;
         }
         if (!fx) {
             av_log(avctx, AV_LOG_ERROR, "Could not get media type.\n");
             goto error;
         }
 

         codec->codec_type  = AVMEDIA_TYPE_AUDIO;

         codec->sample_fmt  = sample_fmt_bits_per_sample(fx->wBitsPerSample);
         codec->codec_id    = waveform_codec_id(codec->sample_fmt);
         codec->sample_rate = fx->nSamplesPerSec;
         codec->channels    = fx->nChannels;
     }
 

     avpriv_set_pts_info(st, 64, 1, 10000000);

 
     ret = 0;
 
 error:
     return ret;
 }
 
 static int parse_device_name(AVFormatContext *avctx)
 {
     struct dshow_ctx *ctx = avctx->priv_data;
     char **device_name = ctx->device_name;
     char *name = av_strdup(avctx->filename);
     char *tmp = name;
     int ret = 1;
     char *type;
 
     while ((type = strtok(tmp, "="))) {
         char *token = strtok(NULL, ":");
         tmp = NULL;
 
         if        (!strcmp(type, "video")) {
             device_name[0] = token;
         } else if (!strcmp(type, "audio")) {
             device_name[1] = token;
         } else {
             device_name[0] = NULL;
             device_name[1] = NULL;
             break;
         }
     }
 
     if (!device_name[0] && !device_name[1]) {
         ret = 0;
     } else {
         if (device_name[0])
             device_name[0] = av_strdup(device_name[0]);
         if (device_name[1])
             device_name[1] = av_strdup(device_name[1]);
     }
 
     av_free(name);
     return ret;
 }
 

 static int dshow_read_header(AVFormatContext *avctx)

 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IGraphBuilder *graph = NULL;
     ICreateDevEnum *devenum = NULL;
     IMediaControl *control = NULL;

     IMediaEvent *media_event = NULL;
     HANDLE media_event_handle;
     HANDLE proc;

     int ret = AVERROR(EIO);
     int r;
 

     CoInitialize(0);
 

     if (!ctx->list_devices && !parse_device_name(avctx)) {

         av_log(avctx, AV_LOG_ERROR, "Malformed dshow input string.\n");
         goto error;
     }
 

     ctx->video_codec_id = avctx->video_codec_id ? avctx->video_codec_id
                                                 : AV_CODEC_ID_RAWVIDEO;

     if (ctx->pixel_format != AV_PIX_FMT_NONE) {

         if (ctx->video_codec_id != AV_CODEC_ID_RAWVIDEO) {
             av_log(avctx, AV_LOG_ERROR, "Pixel format may only be set when "
                               "video codec is not set or set to rawvideo\n");
             ret = AVERROR(EINVAL);
             goto error;
         }
     }

     if (ctx->framerate) {
         r = av_parse_video_rate(&ctx->requested_framerate, ctx->framerate);
         if (r < 0) {
             av_log(avctx, AV_LOG_ERROR, "Could not parse framerate '%s'.\n", ctx->framerate);
             goto error;
         }
     }
 

     r = CoCreateInstance(&CLSID_FilterGraph, NULL, CLSCTX_INPROC_SERVER,
                          &IID_IGraphBuilder, (void **) &graph);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not create capture graph.\n");
         goto error;
     }
     ctx->graph = graph;
 
     r = CoCreateInstance(&CLSID_SystemDeviceEnum, NULL, CLSCTX_INPROC_SERVER,
                          &IID_ICreateDevEnum, (void **) &devenum);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not enumerate system devices.\n");
         goto error;
     }
 

     if (ctx->list_devices) {
         av_log(avctx, AV_LOG_INFO, "DirectShow video devices\n");
         dshow_cycle_devices(avctx, devenum, VideoDevice, NULL);
         av_log(avctx, AV_LOG_INFO, "DirectShow audio devices\n");
         dshow_cycle_devices(avctx, devenum, AudioDevice, NULL);
         ret = AVERROR_EXIT;
         goto error;
     }

     if (ctx->list_options) {
         if (ctx->device_name[VideoDevice])
             dshow_list_device_options(avctx, devenum, VideoDevice);
         if (ctx->device_name[AudioDevice])
             dshow_list_device_options(avctx, devenum, AudioDevice);
         ret = AVERROR_EXIT;
         goto error;
     }

     if (ctx->device_name[VideoDevice]) {

         if ((r = dshow_open_device(avctx, devenum, VideoDevice)) < 0 ||
             (r = dshow_add_device(avctx, VideoDevice)) < 0) {
             ret = r;

             goto error;

         }

     }
     if (ctx->device_name[AudioDevice]) {

         if ((r = dshow_open_device(avctx, devenum, AudioDevice)) < 0 ||
             (r = dshow_add_device(avctx, AudioDevice)) < 0) {
             ret = r;

             goto error;

         }

     }

     ctx->curbufsize[0] = 0;
     ctx->curbufsize[1] = 0;

     ctx->mutex = CreateMutex(NULL, 0, NULL);
     if (!ctx->mutex) {
         av_log(avctx, AV_LOG_ERROR, "Could not create Mutex\n");
         goto error;
     }

     ctx->event[1] = CreateEvent(NULL, 1, 0, NULL);
     if (!ctx->event[1]) {

         av_log(avctx, AV_LOG_ERROR, "Could not create Event\n");
         goto error;
     }
 
     r = IGraphBuilder_QueryInterface(graph, &IID_IMediaControl, (void **) &control);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not get media control.\n");
         goto error;
     }
     ctx->control = control;
 

     r = IGraphBuilder_QueryInterface(graph, &IID_IMediaEvent, (void **) &media_event);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not get media event.\n");
         goto error;
     }
     ctx->media_event = media_event;
 
     r = IMediaEvent_GetEventHandle(media_event, (void *) &media_event_handle);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not get media event handle.\n");
         goto error;
     }
     proc = GetCurrentProcess();
     r = DuplicateHandle(proc, media_event_handle, proc, &ctx->event[0],
                         0, 0, DUPLICATE_SAME_ACCESS);
     if (!r) {
         av_log(avctx, AV_LOG_ERROR, "Could not duplicate media event handle.\n");
         goto error;
     }
 

     r = IMediaControl_Run(control);
     if (r == S_FALSE) {
         OAFilterState pfs;
         r = IMediaControl_GetState(control, 0, &pfs);
     }
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not run filter\n");
         goto error;
     }
 
     ret = 0;
 
 error:
 
     if (devenum)
         ICreateDevEnum_Release(devenum);
 

     if (ret < 0)
         dshow_read_close(avctx);
 

     return ret;
 }
 

 /**
  * Checks media events from DirectShow and returns -1 on error or EOF. Also
  * purges all events that might be in the event queue to stop the trigger
  * of event notification.
  */
 static int dshow_check_event_queue(IMediaEvent *media_event)
 {
     LONG_PTR p1, p2;
     long code;
     int ret = 0;
 
     while (IMediaEvent_GetEvent(media_event, &code, &p1, &p2, 0) != E_ABORT) {
         if (code == EC_COMPLETE || code == EC_DEVICE_LOST || code == EC_ERRORABORT)
             ret = -1;
         IMediaEvent_FreeEventParams(media_event, code, p1, p2);
     }
 
     return ret;
 }
 

 static int dshow_read_packet(AVFormatContext *s, AVPacket *pkt)
 {
     struct dshow_ctx *ctx = s->priv_data;
     AVPacketList *pktl = NULL;
 

     while (!ctx->eof && !pktl) {

         WaitForSingleObject(ctx->mutex, INFINITE);
         pktl = ctx->pktl;

         if (pktl) {
             *pkt = pktl->pkt;

             ctx->pktl = ctx->pktl->next;
             av_free(pktl);

             ctx->curbufsize[pkt->stream_index] -= pkt->size;

         }

         ResetEvent(ctx->event[1]);

         ReleaseMutex(ctx->mutex);
         if (!pktl) {

             if (dshow_check_event_queue(ctx->media_event) < 0) {
                 ctx->eof = 1;
             } else if (s->flags & AVFMT_FLAG_NONBLOCK) {

                 return AVERROR(EAGAIN);
             } else {

                 WaitForMultipleObjects(2, ctx->event, 0, INFINITE);

             }
         }
     }
 

     return ctx->eof ? AVERROR(EIO) : pkt->size;

 }
 

 #define OFFSET(x) offsetof(struct dshow_ctx, x)
 #define DEC AV_OPT_FLAG_DECODING_PARAM
 static const AVOption options[] = {

     { "video_size", "set video size given a string such as 640x480 or hd720.", OFFSET(requested_width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC },

     { "pixel_format", "set video pixel format", OFFSET(pixel_format), AV_OPT_TYPE_PIXEL_FMT, {.i64 = AV_PIX_FMT_NONE}, -1, INT_MAX, DEC },

     { "framerate", "set video frame rate", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },

     { "sample_rate", "set audio sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, DEC },
     { "sample_size", "set audio sample size", OFFSET(sample_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 16, DEC },
     { "channels", "set number of audio channels, such as 1 or 2", OFFSET(channels), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, DEC },
     { "list_devices", "list available devices", OFFSET(list_devices), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, DEC, "list_devices" },

     { "true", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, DEC, "list_devices" },
     { "false", "", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, DEC, "list_devices" },

     { "list_options", "list available options for specified device", OFFSET(list_options), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, DEC, "list_options" },

     { "true", "", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, DEC, "list_options" },
     { "false", "", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, DEC, "list_options" },

     { "video_device_number", "set video device number for devices with same name (starts at 0)", OFFSET(video_device_number), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, DEC },
     { "audio_device_number", "set audio device number for devices with same name (starts at 0)", OFFSET(audio_device_number), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, DEC },
     { "audio_buffer_size", "set audio device buffer latency size in milliseconds (default is the device's default)", OFFSET(audio_buffer_size), AV_OPT_TYPE_INT, {.i64 = 0}, 0, INT_MAX, DEC },

     { NULL },
 };
 
 static const AVClass dshow_class = {

     .class_name = "dshow indev",

     .item_name  = av_default_item_name,
     .option     = options,
     .version    = LIBAVUTIL_VERSION_INT,

     .category   = AV_CLASS_CATEGORY_DEVICE_VIDEO_INPUT,

 };
 

 AVInputFormat ff_dshow_demuxer = {

     .name           = "dshow",
     .long_name      = NULL_IF_CONFIG_SMALL("DirectShow capture"),
     .priv_data_size = sizeof(struct dshow_ctx),
     .read_header    = dshow_read_header,
     .read_packet    = dshow_read_packet,
     .read_close     = dshow_read_close,
     .flags          = AVFMT_NOFILE,
     .priv_class     = &dshow_class,

 };