[FFmpeg-user] ffplay -f flv - doesn't work?

[Roger Pack]

Hello.
When receiving with ffplay mpegts, this works:

ffmpeg -f lavfi -i testsrc=duration=10:size=1280x720:rate=30
-pix_fmt yuv420p -an -f mpegts - | ffplay -f mpegts -

however, with the following, I get this error message:

ffmpeg -f lavfi -i testsrc=duration=10:size=1280x720:rate=30
-pix_fmt yuv420p -an -f flv - | ffplay -f flv -

[flv @ 044bcf60] Could not find codec parameters (Audio: none, 0 channels)
[flv @ 044bcf60] Estimating duration from bitrate, this may be inaccurate

with with input -i sintel.mpg, it plays the entire thing, then outputs this:

[flv @ 0434cf60] Could not find codec parameters (Audio: none, 0 channels)
[flv @ 0434cf60] Estimating duration from bitrate, this may be inaccurate
pipe:: could not find codec parameters

Is this expected?
Thanks!
-r

full output:

ffmpeg-20120622-git-c17808c-win32-static\bin\ffplay -f flv -
ffplay version N-41843-gc17808c Copyright (c) 2003-2012 the FFmpeg developers
  built on Jun 22 2012 17:40:07 with gcc 4.7.1
  configuration: --enable-gpl --enable-version3 --disable-w32threads
--enable-runtime-cpudetect --enable-avisynth --enable-bzlib
--enable-frei0r --enable-libass --enable-libcelt
--enable-libopencore-amrnb --enable-libopencore-amrwb
--enable-libfreetype --enable-libgsm --enable-libmp3lame
--enable-libnut --enable-libopenjpeg --enable-librtmp
--enable-libschroedinger --enable-libspeex --enable-libtheora
--enable-libutvideo --enable-libvo-aacenc --effmpeg
versible-Na-b4l5e2-7l9i-bgv6ob-8a6mdrdwbenc 5--enable-lib Copyright
(c) 2000-2012 the FFmpeg developersvorbis --ena
bxbvpx --ena  built on Oct 10 2012 17:30:47 with gcc 4.7.1 (GCC)ble-li
264 --enable-  configuration: --enable-memalign-hack --arch=x86
--enable-gpl --enable-libx264 --enable-avisynth --enable-libxvid
--target-os=mingw32 --crodowlpirbexfaivxs=
/-h-oemnea/brloeg-elridbpxavcikd/ d-e-ve/nfafbmlpee-gz-lwiibn
rsbuild-helpe  libavutil      51. 61.100 / 51. 61.100
ngandbox/mi  libavcodec     54. 29.100 / 54. 29.100
biw64-i686/  libavformat    54. 11.100 / 54. 11.100
mii686-w64-  libavdevice    54.  0.100 / 54.  0.100
g-w32- --pk  libavfilter     2. 82.100 /  2. 82.100
config=pkg-  libswscale      2.  1.100 /  2.  1.100
bmp--enable-li  libswresample   0. 15.100 /  0. 15.100
leame --enab  libpostproc    52.  0.100 / 52.  0.100
-version3 --enable-libvpx --extra-libs=-lws2_32 --extra-libs=-lpthread
--enable-zlib --extra-libs=-lwinmm --extra-libs=-lgdi32
--enable-librtmp --enable-libvorbis --enable-libtheora
--enable-libspeex --enable-libopenjpeg --enable-gnutls --enable-libgsm
--enable-libfreetype --disable-optimizations --enable-mmx
--disable-postproc --enable-fontconfig --enable-libass
--enable-libutvideo --enable-libopus --disable-w32threads
--extra-cflags=-DPTW32_STATIC_LIB --enable-frei0r
--enable-filter=frei0r --enable-libvo-aacenc
--enable-runtime-cpudetect
  libavutil      51. 74.100 / 51. 74.100
  libavcodec     54. 65.100 / 54. 65.100
  libavformat    54. 31.100 / 54. 31.100
  libavdevice    54.  3.100 / 54.  3.100
  libavfilter     3. 19.102 /  3. 19.102
  libswscale      2.  1.101 /  2.  1.101
  libswresample   0. 16.100 /  0. 16.100
[mpeg2video @ 03B8D8E0] ac-tex damaged at 40 7
[mpeg2video @ 03B8D8E0] Warning MVs not available
[mpeg2video @ 03B8D8E0] concealing 1035 DC, 1035 AC, 1035 MV errors in I frame
[mpeg @ 03B90820] max_analyze_duration 5000000 reached at 5024000
Input #0, mpeg, from 'sintel.mpg':
  Duration: 00:14:47.58, start: 0.233367, bitrate: 4132 kb/s
    Stream #0:0[0x1e0]: Video: mpeg2video (Main), yuv420p, 720x480
[SAR 32:27 DAR 16:9], 7000 kb/s, 29.97 fps, 29.97 tbr, 90k tbn, 59.94
tbc
    Stream #0:1[0x80]: Audio: ac3, 48000 Hz, 5.1(side), s16, 448 kb/s
Output #0, flv, to 'pipe:':
  Metadata:
    encoder         : Lavf54.31.100
    Stream #0:0: Video: flv1 ([2][0][0][0] / 0x0002), yuv420p, 720x480
[SAR 32:27 DAR 16:9], q=2-31, 200 kb/s, 1k tbn, 29.97 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (mpeg2video -> flv)
Press [q] to stop, [?] for help
[mpeg2video @ 03B8D8E0] ac-tex damaged at 40 7
[mpeg2video @ 03B8D8E0] Warning MVs not available
[mpeg2video @ 03B8D8E0] concealing 1035 DC, 1035 AC, 1035 MV errors in I frame
warning: first frame is no keyframe49574kB time=00:13:35.34 bitrate=
498.1kbits/s
Warning MVs not available0 size=   52213kB time=00:14:42.21 bitrate=
484.8kbits/s
[mpeg2video @ 03B8D8E0] concealing 220 DC, 220 AC, 220 MV errors in I frame
frame=24180 fps=322 q=31.0 Lsize=   52533kB time=00:14:47.52 bitrate=
484.9kbits/s
video:52155kB audio:0kB subtitle:0 global headers:0kB muxing overhead 0.724829%
[flv @ 0434cf60] Could not find codec parameters (Audio: none, 0 channels)
[flv @ 0434cf60] Estimating duration from bitrate, this may be inaccurate
pipe:: could not find codec parameters