/*
  * 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 "dshow_capture.h"

 #include "libavutil/parseutils.h"

 #include "libavutil/pixdesc.h"

 #include "libavutil/opt.h"

 #include "libavformat/internal.h"

 #include "libavformat/riff.h"

 #include "avdevice.h"

 #include "libavcodec/raw.h"

 #include "objidl.h"
 #include "shlwapi.h"

 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]);
 

     av_freep(&ctx->device_name[0]);
     av_freep(&ctx->device_name[1]);
     av_freep(&ctx->device_unique_name[0]);
     av_freep(&ctx->device_unique_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_packet_unref(&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;

     const char *devtypename = (devtype == VideoDevice) ? "video" : "audio";

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

               "real-time buffer [%s] [%s input] too full or near too full (%d%% of size: %d [rtbufsize parameter])! frame dropped!\n",
               ctx->device_name[devtype], devtypename, 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, enum dshowSourceFilterType sourcetype,
                     IBaseFilter **pfilter, char **device_unique_name)

 {
     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 only";
     const char *sourcetypename = (sourcetype == VideoSourceDevice) ? "video" : "audio";

     r = ICreateDevEnum_CreateClassEnumerator(devenum, device_guid[sourcetype],

                                              (IEnumMoniker **) &classenum, 0);
     if (r != S_OK) {

         av_log(avctx, AV_LOG_ERROR, "Could not enumerate %s devices (or none found).\n",

                devtypename);

         return AVERROR(EIO);

     }
 

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

         IPropertyBag *bag = NULL;

         char *friendly_name = NULL;
         char *unique_name = NULL;

         VARIANT var;

         IBindCtx *bind_ctx = NULL;
         LPOLESTR olestr = NULL;
         LPMALLOC co_malloc = NULL;
         int i;
 
         r = CoGetMalloc(1, &co_malloc);

         if (r != S_OK)

             goto fail1;
         r = CreateBindCtx(0, &bind_ctx);
         if (r != S_OK)
             goto fail1;
         /* GetDisplayname works for both video and audio, DevicePath doesn't */
         r = IMoniker_GetDisplayName(m, bind_ctx, NULL, &olestr);
         if (r != S_OK)
             goto fail1;
         unique_name = dup_wchar_to_utf8(olestr);
         /* replace ':' with '_' since we use : to delineate between sources */
         for (i = 0; i < strlen(unique_name); i++) {
             if (unique_name[i] == ':')
                 unique_name[i] = '_';
         }
 

         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;

         friendly_name = dup_wchar_to_utf8(var.bstrVal);

         if (pfilter) {

             if (strcmp(device_name, friendly_name) && strcmp(device_name, unique_name))

                 goto fail1;

             if (!skip--) {
                 r = IMoniker_BindToObject(m, 0, 0, &IID_IBaseFilter, (void *) &device_filter);
                 if (r != S_OK) {
                     av_log(avctx, AV_LOG_ERROR, "Unable to BindToObject for %s\n", device_name);
                     goto fail1;
                 }

                 *device_unique_name = unique_name;
                 // success, loop will end now

             }

         } else {

             av_log(avctx, AV_LOG_INFO, " \"%s\"\n", friendly_name);
             av_log(avctx, AV_LOG_INFO, "    Alternative name \"%s\"\n", unique_name);

             av_free(unique_name);

         }

 
 fail1:

         if (olestr && co_malloc)
             IMalloc_Free(co_malloc, olestr);
         if (bind_ctx)
             IBindCtx_Release(bind_ctx);
         av_free(friendly_name);

         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 with name [%s] among source devices of type %s.\n",
                    devtypename, device_name, sourcetypename);

             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, r;

 
     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++) {

         r = IAMStreamConfig_GetStreamCaps(config, i, &type, (void *) caps);
         if (r != S_OK)
             goto next;

 #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);

     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;
 }
 
 /**

  * Pops up a user dialog allowing them to adjust properties for the given filter, if possible.
  */
 void
 dshow_show_filter_properties(IBaseFilter *device_filter, AVFormatContext *avctx) {
     ISpecifyPropertyPages *property_pages = NULL;
     IUnknown *device_filter_iunknown = NULL;
     HRESULT hr;

     FILTER_INFO filter_info = {0}; /* a warning on this line is false positive GCC bug 53119 AFAICT */

     CAUUID ca_guid = {0};
 
     hr  = IBaseFilter_QueryInterface(device_filter, &IID_ISpecifyPropertyPages, (void **)&property_pages);
     if (hr != S_OK) {
         av_log(avctx, AV_LOG_WARNING, "requested filter does not have a property page to show");
         goto end;
     }
     hr = IBaseFilter_QueryFilterInfo(device_filter, &filter_info);
     if (hr != S_OK) {
         goto fail;
     }
     hr = IBaseFilter_QueryInterface(device_filter, &IID_IUnknown, (void **)&device_filter_iunknown);
     if (hr != S_OK) {
         goto fail;
     }
     hr = ISpecifyPropertyPages_GetPages(property_pages, &ca_guid);
     if (hr != S_OK) {
         goto fail;
     }
     hr = OleCreatePropertyFrame(NULL, 0, 0, filter_info.achName, 1, &device_filter_iunknown, ca_guid.cElems,
         ca_guid.pElems, 0, 0, NULL);
     if (hr != S_OK) {
         goto fail;
     }
     goto end;
 fail:
     av_log(avctx, AV_LOG_ERROR, "Failure showing property pages for filter");
 end:
     if (property_pages)
         ISpecifyPropertyPages_Release(property_pages);
     if (device_filter_iunknown)
         IUnknown_Release(device_filter_iunknown);
     if (filter_info.pGraph)
         IFilterGraph_Release(filter_info.pGraph);
     if (ca_guid.pElems)
         CoTaskMemFree(ca_guid.pElems);
 }
 
 /**

  * 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,

                  enum dshowSourceFilterType sourcetype, 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 only";
     const char *sourcetypename = (sourcetype == VideoSourceDevice) ? "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;

     int should_show_properties = (devtype == VideoDevice) ? ctx->show_video_device_dialog : ctx->show_audio_device_dialog;
 
     if (should_show_properties)
         dshow_show_filter_properties(device_filter, avctx);

     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 (from %s devices)\n",
                devtypename, sourcetypename);

     }

     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;

         char *name_buf = NULL;
         wchar_t *pin_id = NULL;
         char *pin_buf = NULL;
         char *desired_pin_name = devtype == VideoDevice ? ctx->video_pin_name : ctx->audio_pin_name;

 
         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;

         name_buf = dup_wchar_to_utf8(info.achName);
 
         r = IPin_QueryId(pin, &pin_id);
         if (r != S_OK) {
             av_log(avctx, AV_LOG_ERROR, "Could not query pin id\n");
             return AVERROR(EIO);
         }
         pin_buf = dup_wchar_to_utf8(pin_id);
 

         if (!ppin) {

             av_log(avctx, AV_LOG_INFO, " Pin \"%s\" (alternative pin name \"%s\")\n", name_buf, pin_buf);

             dshow_cycle_formats(avctx, devtype, pin, NULL);
             goto next;
         }

         if (desired_pin_name) {
             if(strcmp(name_buf, desired_pin_name) && strcmp(pin_buf, desired_pin_name)) {
                 av_log(avctx, AV_LOG_DEBUG, "skipping pin \"%s\" (\"%s\") != requested \"%s\"\n",
                     name_buf, pin_buf, desired_pin_name);
                 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);

         /* in case format_set was not called, just verify the majortype */

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

             if (IsEqualGUID(&type->majortype, mediatype[devtype])) {
                 device_pin = pin;

                 av_log(avctx, AV_LOG_DEBUG, "Selecting pin %s on %s\n", name_buf, devtypename);

                 goto next;
             }
             CoTaskMemFree(type);
         }
 
 next:
         if (types)
             IEnumMediaTypes_Release(types);
         if (p)
             IKsPropertySet_Release(p);
         if (device_pin != pin)
             IPin_Release(pin);

         av_free(name_buf);
         av_free(pin_buf);
         if (pin_id)
             CoTaskMemFree(pin_id);

     }
 

     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, source filter type sourcetype

  *
  * @param devenum device enumerator used for accessing the device
  */
 static int
 dshow_list_device_options(AVFormatContext *avctx, ICreateDevEnum *devenum,

                           enum dshowDeviceType devtype, enum dshowSourceFilterType sourcetype)

 {

     struct dshow_ctx *ctx = avctx->priv_data;

     IBaseFilter *device_filter = NULL;

     char *device_unique_name = NULL;

     int r;
 

     if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_unique_name)) < 0)

         return r;

     ctx->device_filter[devtype] = device_filter;

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

         return r;

     av_freep(&device_unique_name);

     return 0;
 }
 
 static int

 dshow_open_device(AVFormatContext *avctx, ICreateDevEnum *devenum,
                   enum dshowDeviceType devtype, enum dshowSourceFilterType sourcetype)

 {
     struct dshow_ctx *ctx = avctx->priv_data;
     IBaseFilter *device_filter = NULL;

     char *device_filter_unique_name = NULL;

     IGraphBuilder *graph = ctx->graph;
     IPin *device_pin = NULL;
     libAVPin *capture_pin = NULL;
     libAVFilter *capture_filter = NULL;

     ICaptureGraphBuilder2 *graph_builder2 = NULL;

     int ret = AVERROR(EIO);
     int r;

     IStream *ifile_stream = NULL;
     IStream *ofile_stream = NULL;
     IPersistStream *pers_stream = NULL;

     enum dshowDeviceType otherDevType = (devtype == VideoDevice) ? AudioDevice : VideoDevice;

 
     const wchar_t *filter_name[2] = { L"Audio capture filter", L"Video capture filter" };
 

 
     if ( ((ctx->audio_filter_load_file) && (strlen(ctx->audio_filter_load_file)>0) && (sourcetype == AudioSourceDevice)) ||
             ((ctx->video_filter_load_file) && (strlen(ctx->video_filter_load_file)>0) && (sourcetype == VideoSourceDevice)) ) {
         HRESULT hr;
         char *filename = NULL;
 
         if (sourcetype == AudioSourceDevice)
             filename = ctx->audio_filter_load_file;
         else
             filename = ctx->video_filter_load_file;
 
         hr = SHCreateStreamOnFile ((LPCSTR) filename, STGM_READ, &ifile_stream);
         if (S_OK != hr) {
             av_log(avctx, AV_LOG_ERROR, "Could not open capture filter description file.\n");
             goto error;
         }
 
         hr = OleLoadFromStream(ifile_stream, &IID_IBaseFilter, (void **) &device_filter);
         if (hr != S_OK) {
             av_log(avctx, AV_LOG_ERROR, "Could not load capture filter from file.\n");
             goto error;
         }
 
         if (sourcetype == AudioSourceDevice)
             av_log(avctx, AV_LOG_INFO, "Audio-");
         else
             av_log(avctx, AV_LOG_INFO, "Video-");
         av_log(avctx, AV_LOG_INFO, "Capture filter loaded successfully from file \"%s\".\n", filename);
     } else {
 

         if ((r = dshow_cycle_devices(avctx, devenum, devtype, sourcetype, &device_filter, &device_filter_unique_name)) < 0) {

             ret = r;
             goto error;
         }

     }

         if (ctx->device_filter[otherDevType]) {
         // avoid adding add two instances of the same device to the graph, one for video, one for audio
         // a few devices don't support this (could also do this check earlier to avoid double crossbars, etc. but they seem OK)
         if (strcmp(device_filter_unique_name, ctx->device_unique_name[otherDevType]) == 0) {
           av_log(avctx, AV_LOG_DEBUG, "reusing previous graph capture filter... %s\n", device_filter_unique_name);
           IBaseFilter_Release(device_filter);
           device_filter = ctx->device_filter[otherDevType];
           IBaseFilter_AddRef(ctx->device_filter[otherDevType]);
         } else {
             av_log(avctx, AV_LOG_DEBUG, "not reusing previous graph capture filter %s != %s\n", device_filter_unique_name, ctx->device_unique_name[otherDevType]);
         }
     }

 
     ctx->device_filter [devtype] = device_filter;

     ctx->device_unique_name [devtype] = device_filter_unique_name;

 
     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, sourcetype, 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;
 

     if ( ((ctx->audio_filter_save_file) && (strlen(ctx->audio_filter_save_file)>0) && (sourcetype == AudioSourceDevice)) ||
             ((ctx->video_filter_save_file) && (strlen(ctx->video_filter_save_file)>0) && (sourcetype == VideoSourceDevice)) ) {
 
         HRESULT hr;
         char *filename = NULL;
 
         if (sourcetype == AudioSourceDevice)
             filename = ctx->audio_filter_save_file;
         else
             filename = ctx->video_filter_save_file;
 
         hr = SHCreateStreamOnFile ((LPCSTR) filename, STGM_CREATE | STGM_READWRITE, &ofile_stream);
         if (S_OK != hr) {
             av_log(avctx, AV_LOG_ERROR, "Could not create capture filter description file.\n");
             goto error;
         }
 
         hr  = IBaseFilter_QueryInterface(device_filter, &IID_IPersistStream, (void **) &pers_stream);
         if (hr != S_OK) {
             av_log(avctx, AV_LOG_ERROR, "Query for IPersistStream failed.\n");
             goto error;
         }
 
         hr = OleSaveToStream(pers_stream, ofile_stream);
         if (hr != S_OK) {
             av_log(avctx, AV_LOG_ERROR, "Could not save capture filter \n");
             goto error;
         }
 
         hr = IStream_Commit(ofile_stream, STGC_DEFAULT);
         if (S_OK != hr) {
             av_log(avctx, AV_LOG_ERROR, "Could not commit capture filter data to file.\n");
             goto error;
         }
 
         if (sourcetype == AudioSourceDevice)
             av_log(avctx, AV_LOG_INFO, "Audio-");
         else
             av_log(avctx, AV_LOG_INFO, "Video-");
         av_log(avctx, AV_LOG_INFO, "Capture filter saved successfully to file \"%s\".\n", filename);
     }
 

     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 = CoCreateInstance(&CLSID_CaptureGraphBuilder2, NULL, CLSCTX_INPROC_SERVER,
                          &IID_ICaptureGraphBuilder2, (void **) &graph_builder2);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not create CaptureGraphBuilder2\n");
         goto error;
     }
     ICaptureGraphBuilder2_SetFiltergraph(graph_builder2, graph);
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not set graph for CaptureGraphBuilder2\n");
         goto error;
     }
 
     r = ICaptureGraphBuilder2_RenderStream(graph_builder2, NULL, NULL, (IUnknown *) device_pin, NULL /* no intermediate filter */,
         (IBaseFilter *) capture_filter); /* connect pins, optionally insert intermediate filters like crossbar if necessary */
 
     if (r != S_OK) {
         av_log(avctx, AV_LOG_ERROR, "Could not RenderStream to connect pins\n");
         goto error;
     }
 
     r = dshow_try_setup_crossbar_options(graph_builder2, device_filter, devtype, avctx);
 

     if (r != S_OK) {

         av_log(avctx, AV_LOG_ERROR, "Could not setup CrossBar\n");

         goto error;
     }
 
     ret = 0;
 
 error:

     if (graph_builder2 != NULL)
         ICaptureGraphBuilder2_Release(graph_builder2);
 

     if (pers_stream)
         IPersistStream_Release(pers_stream);
 
     if (ifile_stream)
         IStream_Release(ifile_stream);
 
     if (ofile_stream)
         IStream_Release(ofile_stream);
 

     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;

     AVCodecParameters *par;

     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);
 

     par = st->codecpar;

     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;
         }
 

         st->avg_frame_rate = av_inv_q(time_base);

         st->r_frame_rate = av_inv_q(time_base);

 
         par->codec_type = AVMEDIA_TYPE_VIDEO;
         par->width      = bih->biWidth;
         par->height     = bih->biHeight;
         par->codec_tag  = bih->biCompression;
         par->format     = 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");

             par->color_range = AVCOL_RANGE_MPEG; // just in case it needs this...

         }

         if (par->format == AV_PIX_FMT_NONE) {

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

             par->codec_id = av_codec_get_id(tags, bih->biCompression);
             if (par->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;
             }

             par->bits_per_coded_sample = bih->biBitCount;

         } else {

             par->codec_id = AV_CODEC_ID_RAWVIDEO;

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

                 par->bits_per_coded_sample = bih->biBitCount;

                 if (par->height < 0) {
                     par->height *= -1;
                 } else {

                     par->extradata = av_malloc(9 + AV_INPUT_BUFFER_PADDING_SIZE);
                     if (par->extradata) {
                         par->extradata_size = 9;
                         memcpy(par->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;
         }
 

         par->codec_type  = AVMEDIA_TYPE_AUDIO;
         par->format      = sample_fmt_bits_per_sample(fx->wBitsPerSample);
         par->codec_id    = waveform_codec_id(par->format);
         par->sample_rate = fx->nSamplesPerSec;
         par->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->url);

     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 (some may be both video and audio devices)\n");

         dshow_cycle_devices(avctx, devenum, VideoDevice, VideoSourceDevice, NULL, NULL);

         av_log(avctx, AV_LOG_INFO, "DirectShow audio devices\n");

         dshow_cycle_devices(avctx, devenum, AudioDevice, AudioSourceDevice, NULL, NULL);

         ret = AVERROR_EXIT;
         goto error;
     }

     if (ctx->list_options) {
         if (ctx->device_name[VideoDevice])

             if ((r = dshow_list_device_options(avctx, devenum, VideoDevice, VideoSourceDevice))) {

                 ret = r;
                 goto error;
             }

         if (ctx->device_name[AudioDevice]) {
             if (dshow_list_device_options(avctx, devenum, AudioDevice, AudioSourceDevice)) {
                 /* show audio options from combined video+audio sources as fallback */
                 if ((r = dshow_list_device_options(avctx, devenum, AudioDevice, VideoSourceDevice))) {
                     ret = r;
                     goto error;
                 }

             }

         }

     }

     if (ctx->device_name[VideoDevice]) {

         if ((r = dshow_open_device(avctx, devenum, VideoDevice, VideoSourceDevice)) < 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, AudioSourceDevice)) < 0 ||

             (r = dshow_add_device(avctx, AudioDevice)) < 0) {

             av_log(avctx, AV_LOG_INFO, "Searching for audio device within video devices for %s\n", ctx->device_name[AudioDevice]);

             /* see if there's a video source with an audio pin with the given audio name */
             if ((r = dshow_open_device(avctx, devenum, AudioDevice, VideoSourceDevice)) < 0 ||
                 (r = dshow_add_device(avctx, AudioDevice)) < 0) {
                 ret = r;
                 goto error;
             }

         }

     }

     if (ctx->list_options) {
         /* allow it to list crossbar options in dshow_open_device */
         ret = AVERROR_EXIT;
         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 graph (sometimes caused by a device already in use by other application)\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 },

     { "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 },

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

     { "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 },

     { "video_pin_name", "select video capture pin by name", OFFSET(video_pin_name),AV_OPT_TYPE_STRING, {.str = NULL},  0, 0, AV_OPT_FLAG_ENCODING_PARAM },
     { "audio_pin_name", "select audio capture pin by name", OFFSET(audio_pin_name),AV_OPT_TYPE_STRING, {.str = NULL},  0, 0, AV_OPT_FLAG_ENCODING_PARAM },

     { "crossbar_video_input_pin_number", "set video input pin number for crossbar device", OFFSET(crossbar_video_input_pin_number), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, DEC },
     { "crossbar_audio_input_pin_number", "set audio input pin number for crossbar device", OFFSET(crossbar_audio_input_pin_number), AV_OPT_TYPE_INT, {.i64 = -1}, -1, INT_MAX, DEC },

     { "show_video_device_dialog",              "display property dialog for video capture device",                            OFFSET(show_video_device_dialog),              AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { "show_audio_device_dialog",              "display property dialog for audio capture device",                            OFFSET(show_audio_device_dialog),              AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { "show_video_crossbar_connection_dialog", "display property dialog for crossbar connecting pins filter on video device", OFFSET(show_video_crossbar_connection_dialog), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { "show_audio_crossbar_connection_dialog", "display property dialog for crossbar connecting pins filter on audio device", OFFSET(show_audio_crossbar_connection_dialog), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { "show_analog_tv_tuner_dialog",           "display property dialog for analog tuner filter",                             OFFSET(show_analog_tv_tuner_dialog),           AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },
     { "show_analog_tv_tuner_audio_dialog",     "display property dialog for analog tuner audio filter",                       OFFSET(show_analog_tv_tuner_audio_dialog),     AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, DEC },

     { "audio_device_load", "load audio capture filter device (and properties) from file", OFFSET(audio_filter_load_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
     { "audio_device_save", "save audio capture filter device (and properties) to file", OFFSET(audio_filter_save_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
     { "video_device_load", "load video capture filter device (and properties) from file", OFFSET(video_filter_load_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
     { "video_device_save", "save video capture filter device (and properties) to file", OFFSET(video_filter_save_file), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, 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,

 };