The VideoLAN Forums

Transmitting a video stream over MPEG-TS UDP Multicast using H264 encoder works great. Except at low bitrates. At 256kbps and below, the video is black. Fine at 512kbps though.

It works fine in ffplay, but in VLC, the audio shows up, but the video is black. Any ideas?

ts debug: * number=1 pid=66
ts debug: PMTCallBack called
ts debug: new PMT program number=1 version=25 pid_pcr=69
ts debug: * es pid=68 type=3 fcc=mpga
main debug: selecting program id=1
qt4 debug: New Event: type 1108
main debug: looking for decoder module: 30 candidates
main debug: using decoder module "mpeg_audio"
main debug: TIMER module_Need() : 0.335 ms - Total 0.335 ms / 1 intvls (Avg 0.335 ms)
main debug: thread started
main debug: thread 2904550288 (decoder) created at priority 5 (input/decoder.c:217)
ts debug: * es pid=69 type=27 fcc=h264
main debug: looking for decoder module: 30 candidates
avcodec debug: libavcodec already initialized
avcodec debug: ffmpeg codec (H264 - MPEG-4 AVC (part 10)) started
main debug: using decoder module "avcodec"
main debug: TIMER module_Need() : 1.201 ms - Total 1.201 ms / 1 intvls (Avg 1.201 ms)
main debug: looking for packetizer module: 18 candidates
main debug: using packetizer module "packetizer_h264"
main debug: TIMER module_Need() : 0.132 ms - Total 0.132 ms / 1 intvls (Avg 0.132 ms)
main debug: thread started
main debug: thread 2948258704 (decoder) created at priority 0 (input/decoder.c:217)
ts warning: first packet for pid=69 cc=0xc
ts warning: first packet for pid=68 cc=0xb
main debug: control type=1
mpeg_audio debug: MPGA channels:2 samplerate:48000 bitrate:192
main debug: no aout present, spawning one
main debug: looking for audio output module: 3 candidates
alsa debug: opening ALSA device `default'
main debug: thread started
packetizer_h264 warning: waiting for SPS/PPS
main debug: thread 2922736528 (aout) created at priority 15 (alsa.c:687)
main debug: using audio output module "alsa"
main debug: TIMER module_Need() : 61.171 ms - Total 61.171 ms / 1 intvls (Avg 61.171 ms)
main debug: output 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
main debug: mixer 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
main debug: no need for any filter
main debug: looking for audio mixer module: 3 candidates
main debug: using audio mixer module "float32_mixer"
main debug: TIMER module_Need() : 0.202 ms - Total 0.202 ms / 1 intvls (Avg 0.202 ms)
main debug: input 'mpga' 48000 Hz Stereo frame=1152 samples/1161 bytes
main debug: filter(s) 'mpga'->'fl32' 48000 Hz->48000 Hz Stereo->Stereo
main debug: looking for audio filter module: 24 candidates
main debug: using audio filter module "mpgatofixed32"
main debug: TIMER module_Need() : 0.092 ms - Total 0.092 ms / 1 intvls (Avg 0.092 ms)
main debug: found a filter for the whole conversion
main debug: filter(s) 'fl32'->'fl32' 52800 Hz->48000 Hz Stereo->Stereo
main debug: looking for audio filter module: 24 candidates
main debug: using audio filter module "bandlimited_resampler"
main debug: TIMER module_Need() : 0.120 ms - Total 0.120 ms / 1 intvls (Avg 0.120 ms)
main debug: found a filter for the whole conversion
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 warning: waiting for SPS/PPS
main warning: output date isn't PTS date, requesting resampling (67791)
main warning: buffer is 67473 late, triggering upsampling
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 warning: waiting for SPS/PPS
packetizer_h264 debug: found NAL_SPS (sps_id=0)
packetizer_h264 debug: found NAL_PPS (pps_id=0 sps_id=0)
main debug: no usable vout present, spawning one
main debug: window size: 435x246
main debug: looking for video output module: 9 candidates
main debug: looking for vout window module: 2 candidates
qt4 debug: waiting for interface...
qt4 debug: requesting window...
qt4 debug: Video was requested -1, -1
qt4 debug: Video is resizing to: 435 246
qt4 debug: Updating the geometry
qt4 debug: Qt FS: Attaching Vout
qt4 debug: Qt: Changing Fullscreen Mode
main debug: using vout window module "qt4"
main debug: TIMER module_Need() : 13.216 ms - Total 13.216 ms / 1 intvls (Avg 13.216 ms)
x11 debug: XShm video extension v1.1 (without pixmaps, opcode: 145)
x11 debug: Window manager supports NetWM
x11 debug: Window manager supports _NET_WM_STATE_FULLSCREEN
x11 debug: Window manager supports _NET_WM_STATE_ABOVE
x11 debug: Window manager supports _NET_WM_STATE_BELOW
main debug: using video output module "x11"
main debug: TIMER module_Need() : 74.515 ms - Total 74.515 ms / 1 intvls (Avg 74.515 ms)
main debug: thread started
x11 debug: x11 image size 435x246 (0,0,435x246)
main debug: waiting for thread initialization
main debug: got 2 direct buffer(s)
main debug: picture in 368x246 (0,0,368x246), chroma I420, ar 16997:9600, sar 2663:2250
main debug: picture user 368x246 (0,0,368x246), chroma I420, ar 16997:9600, sar 2663:2250
main debug: picture out 435x246 (0,0,435x246), chroma RV32, ar 42439:24000, sar 1:1
main debug: looking for video filter2 module: 19 candidates
swscale debug: 368x246 chroma: I420 -> 435x246 chroma: RV32 with scaling using Bicubic (good quality)
main debug: using video filter2 module "swscale"
main debug: TIMER module_Need() : 1.028 ms - Total 1.028 ms / 1 intvls (Avg 1.028 ms)
main debug: indirect render, mapping render pictures 0-7 to system pictures 2-9
main debug: thread 2912942992 (video output) created at priority 15 (video_output/video_output.c:504)
main debug: removing module "swscale"main warning: resampling stopped after 12408819 usec (drift: 88)

qt4 debug: New Event: type 1109
x11 debug: x11 image size 435x246 (0,0,435x246)
main debug: looking for video filter2 module: 19 candidates
swscale debug: 368x246 chroma: I420 -> 435x246 chroma: RV32 with scaling using Bicubic (good quality)
main debug: using video filter2 module "swscale"
main debug: TIMER module_Need() : 1.066 ms - Total 1.066 ms / 1 intvls (Avg 1.066 ms)

which VLC version do you use? To my best knowledge, under windows the latest version were x264 functions is 0.8.6i. Under linux (tested on Ubuntu) x264 also functions in the latest version.

Johan