@@ -1079,6 +1079,45 @@ error:
return ret;
}
+static int dshow_control_message(AVFormatContext *avctx, int type, void *data, size_t data_size)
+{
+ struct dshow_ctx *ctx = avctx->priv_data;
+ int run_state = ctx->is_running;
+ HRESULT hr;
+
+ switch (type) {
+ case AV_APP_TO_DEV_PAUSE:
+ run_state = 0;
+ break;
+ case AV_APP_TO_DEV_PLAY:
+ run_state = 1;
+ break;
+ case AV_APP_TO_DEV_TOGGLE_PAUSE:
+ run_state = !run_state;
+ break;
+ }
+
+ // if play state change requested, apply
+ if (run_state != ctx->is_running) {
+ if (run_state)
+ hr = IMediaControl_Run(ctx->control);
+ else
+ hr = IMediaControl_Pause(ctx->control);
+
+ if (hr == S_FALSE) {
+ OAFilterState pfs;
+ hr = IMediaControl_GetState(ctx->control, 0, &pfs);
+ }
+ if (hr != S_OK) {
+ av_log(avctx, AV_LOG_ERROR, "Could not run/pause graph\n");
+ return AVERROR(EIO);
+ }
+ ctx->is_running = run_state;
+ }
+
+ return 0;
+}
+
static enum AVCodecID waveform_codec_id(enum AVSampleFormat sample_fmt)
{
switch (sample_fmt) {
@@ -1317,6 +1356,7 @@ static int dshow_read_header(AVFormatContext *avctx)
}
}
}
+ ctx->is_running = 0;
if (ctx->device_name[VideoDevice]) {
if ((r = dshow_open_device(avctx, devenum, VideoDevice, VideoSourceDevice)) < 0 ||
(r = dshow_add_device(avctx, VideoDevice)) < 0) {
@@ -1390,6 +1430,7 @@ static int dshow_read_header(AVFormatContext *avctx)
av_log(avctx, AV_LOG_ERROR, "Could not run graph (sometimes caused by a device already in use by other application)\n");
goto error;
}
+ ctx->is_running = 1;
ret = 0;
@@ -1502,6 +1543,7 @@ const AVInputFormat ff_dshow_demuxer = {
.read_packet = dshow_read_packet,
.read_close = dshow_read_close,
.get_device_list= dshow_get_device_list,
+ .control_message = dshow_control_message,
.flags = AVFMT_NOFILE | AVFMT_NOBINSEARCH | AVFMT_NOGENSEARCH | AVFMT_NO_BYTE_SEEK,
.priv_class = &dshow_class,
};
@@ -331,6 +331,7 @@ struct dshow_ctx {
IMediaControl *control;
IMediaEvent *media_event;
+ int is_running;
enum AVPixelFormat pixel_format;
enum AVCodecID video_codec_id;
This allows programmatic users of avdevice to start and stop the DirectShow Capture graph (i.e. receive frames or not). This is important because now the buffer fills up and starts dropping samples when enqueued packets are not read out immediately after the demuxer is opened. Signed-off-by: Diederick Niehorster <dcnieho@gmail.com> --- libavdevice/dshow.c | 42 +++++++++++++++++++++++++++++++++++++ libavdevice/dshow_capture.h | 1 + 2 files changed, 43 insertions(+)