Support for RFC 3640

[kiranantony]

Howdy people..

Question:
Does VLC support aggregation and fragmentation modes as mentioned in RFC 3640, for MPEG4 elementary audio streams..?

My Issue:
I was doing an AAC encode, RTP packetize using Aggregation mode, UDP send and capture data with VLC using a .sdp file. But VLC plays for a while and later gives out "PTS is out of range" message.. I wish to know if its an issue with my RTP server (timestamping most propbably. But initial analysis with Ethereal proves, timestamp is more or less accurate) or whether VLC doesn't support the aggregation mode of operation..

Hope to get a reply soon.. as i'm running short of time..

Thanks in advance
KA

[Jean-Baptiste Kempf]

ask on the mailing lists.

[The DJ]

debug logs and more is required. Also, does the server support RTCP ?

[kiranantony]

This is the VLC Error log:
It shows negative timestamping...

main debug: adding playlist item `C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp' ( C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp )
main debug: creating new input thread
main debug: waiting for thread completion
main debug: thread 4916 (input) created at priority 1 (input/input.c:261)
main warning: drive letter C: found in source
main debug: `C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp' gives access `' demux `' path `C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp'
main debug: creating demux: access='' demux='' path='C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp'
main debug: looking for access_demux module: 1 candidate
main debug: creating access '' path='C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp'
main debug: looking for access2 module: 5 candidates
vcd debug: trying .cue file: C:\Documents and Settings\100388\Desktop\Mpeg4_aac.cue
access_file debug: opening file `C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp'
main debug: using access2 module "access_file"
main debug: pre-buffering...
main debug: received first data for our buffer
main debug: creating demux: access='' demux='' path='C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp'
main debug: looking for demux2 module: 44 candidates
sap debug: incorrect c field, IN
livedotcom debug: sdp=v=0
c=IN IP4 231.0.0.11
m=audio 7890 RTP/AVP 96
a=rtpmap:96 mpeg4-generic/48000/2
a=fmtp:96;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3


livedotcom debug: RTP subsession 'audio/MPEG4-GENERIC'
main debug: selecting program id=0
main debug: using demux2 module "livedotcom"
main debug: looking for a subtitle file in C:\Documents and Settings\100388\Desktop\
main debug: looking for decoder module: 27 candidates
main debug: using decoder module "faad"
main debug: thread 4856 (decoder) created at priority 2 (input/decoder.c:159)
main debug: `C:\Documents and Settings\100388\Desktop\Mpeg4_aac.sdp' successfully opened
faad warning: decoded zero sample
main debug: looking for audio output module: 3 candidates
aout_directx debug: OpenAudio
aout_directx debug: found device: Primary Sound Driver
aout_directx debug: found device: SoundMAX HD Audio
aout_directx debug: device supports 2 channels
aout_directx debug: device supports 1 channel
aout_directx debug: creating DirectSoundThread
main debug: thread 4864 (DirectSound Notification Thread) created at priority 15 (directx.c:372)
aout_directx debug: DirectSoundThread ready
main debug: using audio output module "aout_directx"
main debug: output 's16l' 48000 Hz Stereo frame=1 samples/4 bytes
main debug: mixer 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
main debug: filter(s) 'fl32'->'s16l' 48000 Hz->48000 Hz Stereo->Stereo
main debug: looking for audio filter module: 24 candidates
main debug: using audio filter module "float32tos16"
main debug: found a filter for the whole conversion
main debug: looking for audio mixer module: 3 candidates
main debug: using audio mixer module "trivial_mixer"
main debug: input 'fl32' 48000 Hz Stereo frame=1 samples/8 bytes
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: found a filter for the whole conversion
main warning: output date isn't PTS date, requesting resampling (73916)
main warning: buffer is 49582 late, triggering upsampling
main warning: PTS is out of range (-26000), dropping buffer
main warning: PTS is out of range (-18000), dropping buffer
main warning: PTS is out of range (-39333), dropping buffer
main warning: output date isn't PTS date, requesting resampling (53000)
main warning: PTS is out of range (3000), dropping buffer
main warning: output PTS is out of range (10084), clearing out
main warning: input PTS is out of range (23626), trashing
main warning: input PTS is out of range (2293), trashing
main warning: PTS is out of range (-18333), dropping buffer
main warning: PTS is out of range (-39666), dropping buffer
main warning: buffer is 41960 in advance, triggering downsampling
main warning: computed PTS is out of range (6772), clearing out
main warning: timing screwed, stopping resampling
main warning: PTS is out of range (-35000), dropping buffer
main warning: input PTS is out of range (6773), trashing
main warning: buffer is 62939 in advance, triggering downsampling
main warning: computed PTS is out of range (42086), clearing out
main warning: timing screwed, stopping resampling
main warning: PTS is out of range (-20000), dropping buffer
main warning: input PTS is out of range (42086), trashing
main warning: computed PTS is out of range (20586), clearing out
main warning: PTS is out of range (-11000), dropping buffer
main warning: input PTS is out of range (31334), trashing
main warning: input PTS is out of range (10001), trashing
main warning: PTS is out of range (-32333), dropping buffer
main warning: buffer is 42334 in advance, triggering downsampling
main warning: computed PTS is out of range (24147), clearing out
main warning: timing screwed, stopping resampling
main warning: PTS is out of range (-19000), dropping buffer
main warning: input PTS is out of range (24148), trashing
main warning: computed PTS is out of range (2648), clearing out
main warning: output date isn't PTS date, requesting resampling (81584)
main warning: buffer is 82249 late, triggering upsampling
main warning: PTS is out of range (-35000), dropping buffer
main warning: buffer is 59750 late, triggering upsampling
main warning: PTS is out of range (-37000), dropping buffer
main warning: PTS is out of range (-36000), dropping buffer
main warning: output date isn't PTS date, requesting resampling (41666)
main warning: buffer is 48457 late, triggering upsampling
main warning: PTS is out of range (-34000), dropping buffer
main warning: PTS is out of range (-33000), dropping buffer
main warning: output date isn't PTS date, requesting resampling (57667)
main warning: buffer is 63124 late, triggering upsampling
main warning: PTS is out of range (-39000), dropping buffer
main warning: buffer is 41958 late, triggering upsampling
main warning: PTS is out of range (-16000), dropping buffer
main warning: PTS is out of range (-37333), dropping buffer
main warning: output date isn't PTS date, requesting resampling (47333)
main warning: buffer is 47290 late, triggering upsampling
main warning: output date isn't PTS date, requesting resampling (44334)
main warning: timing screwed, stopping resampling
main warning: buffer is 90937 late, triggering upsampling
main warning: PTS is out of range (-36000), dropping buffer
main warning: output date isn't PTS date, requesting resampling (48333)
main warning: PTS is out of range (-34000), dropping buffer
main warning: buffer is 51874 late, triggering upsampling
main warning: PTS is out of range (-34000), dropping buffer
main warning: PTS is out of range (6000), dropping buffer
main warning: PTS is out of range (-15333), dropping buffer
main warning: PTS is out of range (-36666), dropping buffer
main warning: computed PTS is out of range (33147), clearing out
main warning: PTS is out of range (-1000), dropping buffer
main warning: output PTS is out of range (77417), clearing out
main warning: PTS is out of range (-22333), dropping buffer
main warning: computed PTS is out of range (6668), clearing out
main warning: PTS is out of range (7000), dropping buffer
main warning: PTS is out of range (-14333), dropping buffer
main warning: PTS is out of range (-35666), dropping buffer
main warning: output date isn't PTS date, requesting resampling (68250)
main warning: PTS is out of range (-17000), dropping buffer
main warning: PTS is out of range (-38333), dropping buffer
main warning: PTS is out of range (23000), dropping buffer
main warning: output PTS is out of range (24750), clearing out
main warning: input PTS is out of range (39417), trashing
main warning: input PTS is out of range (18084), trashing
main warning: PTS is out of range (1667), dropping buffer
main warning: PTS is out of range (-19666), dropping buffer
main warning: computed PTS is out of range (53417), clearing out
main warning: PTS is out of range (16000), dropping buffer
main warning: PTS is out of range (-5333), dropping buffer
main warning: PTS is out of range (-10666), dropping buffer
main warning: PTS is out of range (-32000), dropping buffer
main warning: PTS is out of range (71000), dropping buffer
main warning: PTS is out of range (49667), dropping buffer
main warning: PTS is out of range (28334), dropping buffer
main warning: PTS is out of range (7000), dropping buffer
main warning: PTS is out of range (64000), dropping buffer
main warning: PTS is out of range (42667), dropping buffer
main warning: PTS is out of range (21334), dropping buffer
main warning: PTS is out of range (0), dropping buffer
main warning: PTS is out of range (73000), dropping buffer
main warning: PTS is out of range (51667), dropping buffer
main warning: PTS is out of range (30334), dropping buffer
main warning: PTS is out of range (9000), dropping buffer
main warning: PTS is out of range (65000), dropping buffer
main warning: PTS is out of range (43667), dropping buffer
main warning: PTS is out of range (22334), dropping buffer
main warning: PTS is out of range (1000), dropping buffer
main warning: PTS is out of range (27000), dropping buffer
main warning: PTS is out of range (5667), dropping buffer
main warning: PTS is out of range (-15666), dropping buffer
main warning: PTS is out of range (-37000), dropping buffer
main warning: PTS is out of range (20000), dropping buffer
main warning: PTS is out of range (-1333), dropping buffer
main warning: PTS is out of range (-22666), dropping buffer
main warning: computed PTS is out of range (59667), clearing out
main warning: PTS is out of range (59000), dropping buffer
main warning: PTS is out of range (37667), dropping buffer
main warning: PTS is out of range (16334), dropping buffer
main warning: PTS is out of range (-5000), dropping buffer
main warning: PTS is out of range (68000), dropping buffer
main warning: PTS is out of range (46667), dropping buffer
main warning: PTS is out of range (25334), dropping buffer

This is the sdp file used:

v=0
c=IN IP4 231.0.0.11
m=audio 7890 RTP/AVP 96
a=rtpmap:96 mpeg4-generic/48000/2
a=fmtp:96;mode=AAC-hbr;sizelength=13;indexlength=3;indexdeltalength=3

The server supports RTCP, but i've disabled its usage..

The ethereal dump, doesn't show any negative timestamps, and sequence numbers are in order...

[The DJ]

You need RTCP for correct processing of timestamps (This is the problem of times vs. clock aka pace). The lack of RTCP is your primary problem.