FFmpeg streaming: can't see image from h263 stream in flash

Question

I'm using FFmpeg for live rtmp-streaming of my desktop to Wowza. If I publish stream in h264 or flashsv2 codec, everything works fine, but I need h263 support too. The problem is, that I see no images from stream in Flash, if my stream's codec is H263! I catch NetStream.Play.Start event, and even get video's metadata, but no image is displayed in my Video object. There was the same problem with h264, when I tried to stream it with this command:

ffmpeg -f dshow -i video=UScreenCapture -vcodec h264 -f flv rtmp://[adr]/desc

Choosing yuv420p pixel format fixed this bug. So, streaming with the command below, is displayed in proper way in Flash:

ffmpeg -f dshow -i video=UScreenCapture -vcodec h264 -pix_fmt yuv420p -f flv rtmp://[adr]/desc

But when I try to solve the problem with h263 this way, nothing happens: still no image in flash. What I have to do to fix this bug?

Here is my h263 command:

ffmpeg -f dshow -i video=UScreenCapture -vcodec h263 -pix_fmt yuv420p -s 352x288 -f flv rtmp://[adr]/desc

Answer 1

I'm surprised you were able to force 'h263' codec video into a FLV container. The problem is that Flash Player does not support H.263 video. It supports Sorenson Spark, which is a variation of H.263. Access it using the 'flv1' video codec instead.

As an aside, execute ffmpeg -codecs | grep 263 to get an idea for how many variations of H.263 exist.