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->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; }