[Libav-user] Missing timing info when probing custom AVIO Context

Charles Cross charles at openrov.com
Tue Apr 26 10:40:27 CEST 2016


Hi all,

I'm having an issue with avformat_find_stream_info() not pulling the timing
information out of an H264 stream that I am parsing in real time as it
comes off of my camera. I've cobbled together my stream detection code by
reading scattered tutorials, libav-user threads, and diving into the
libavformat/libavcodec code base, so there is much room for error on my
part in how I am trying to achieve this. That said, I think it is prudent
that I start by explaining my use case thoroughly for context, following
which I will provide my code and results.

I have a custom camera built by an OEM which outputs a 1080p at 30fps H264
elementary stream over USB. Its interface is simple: I provide it a
callback that takes a buffer, a size, and void* userData, and it calls that
callback each time it has finished producing a frame. The frame is
guaranteed to be a complete NAL unit. My goal is to take the live stream
from the camera, detect the format of the video, mux each frame into a
fragmented MP4 container (1 NAL unit per container), and shoot each muxed
frame off to another program to be used as a live stream. I am also trying
to get each of these frames through the pipeline with the lowest latency
possible, trying to avoid buffering of any form. For the most part, this
process is working great and I've got live MP4 video streaming in my other
application and rendering correctly. However, in the stream format
detection stage, I get some warning messages and lots of missing fields
when it comes to timing information, and that missing timing information
sometimes causes problems in my other program (and other video services)
when it comes to playback speed.

All of my re-muxing logic is contained in this class:

https://github.com/OpenROV-Dev/geomuxpp/blob/inproc_rewrite/src/CMuxer.h
https://github.com/OpenROV-Dev/geomuxpp/blob/inproc_rewrite/src/CMuxer.cpp

Data is dumped into the CVideoBuffer m_inputBuffer structure by the camera
callback. When data is available, the muxer gets signaled to process the
NAL unit. First it builds up a couple megabytes of data to probe, then it
finds the stream info, and ultimately constructs an output AVIO context for
muxing to MP4 using all of the parsed stream info. Then each packet is
muxed and written out using the custom WritePacket callback which sends the
data out over ZeroMQ.

Here is the output of my program with AV traces on (Note: Using FFMPEG
latest stable source tarball, 3.0.1 from 2/24/16):

-------------------------
---------NEW RUN---------
Channels created: 1
Application Started.
Init success
Input: 21092 bytes at: 1461658579098
Input: 45508 bytes at: 1461658579132
Input: 39348 bytes at: 1461658579165
Input: 37716 bytes at: 1461658579199
Input: 38372 bytes at: 1461658579232
Input: 37016 bytes at: 1461658579265
Input: 37324 bytes at: 1461658579299
Input: 35600 bytes at: 1461658579332
Input: 35400 bytes at: 1461658579365
Input: 36160 bytes at: 1461658579399
Input: 36708 bytes at: 1461658579432
Input: 36472 bytes at: 1461658579465
Input: 36896 bytes at: 1461658579499
Input: 34628 bytes at: 1461658579532
Input: 34728 bytes at: 1461658579565
Input: 34476 bytes at: 1461658579598
Input: 35084 bytes at: 1461658579632
Input: 36344 bytes at: 1461658579665
Input: 36200 bytes at: 1461658579698
Input: 38156 bytes at: 1461658579732
Input: 35280 bytes at: 1461658579765
Input: 34252 bytes at: 1461658579798
Input: 34768 bytes at: 1461658579832
Input: 34612 bytes at: 1461658579865
Input: 35624 bytes at: 1461658579898
Input: 36408 bytes at: 1461658579932
Input: 35048 bytes at: 1461658579965
Input: 35252 bytes at: 1461658579998
Input: 34852 bytes at: 1461658580032
Input: 33968 bytes at: 1461658580065
Input: 34004 bytes at: 1461658580098
Input: 35048 bytes at: 1461658580132
Input: 34676 bytes at: 1461658580165
Input: 35212 bytes at: 1461658580198
Input: 34636 bytes at: 1461658580232
Input: 33448 bytes at: 1461658580265
Input: 34016 bytes at: 1461658580298
Input: 34288 bytes at: 1461658580332
Input: 34244 bytes at: 1461658580365
Input: 34276 bytes at: 1461658580398
Input: 34628 bytes at: 1461658580431
Input: 34212 bytes at: 1461658580465
Input: 33684 bytes at: 1461658580498
Input: 33536 bytes at: 1461658580531
Input: 33520 bytes at: 1461658580565
Input: 35332 bytes at: 1461658580598
Input: 34404 bytes at: 1461658580631
Input: 33956 bytes at: 1461658580665
Input: 33176 bytes at: 1461658580698
Input: 34100 bytes at: 1461658580731
Input: 34072 bytes at: 1461658580765
Input: 33724 bytes at: 1461658580798
Input: 34064 bytes at: 1461658580831
Input: 33976 bytes at: 1461658580865
Input: 33888 bytes at: 1461658580898
Input: 34124 bytes at: 1461658580931
Input: 34008 bytes at: 1461658580965
Input: 33412 bytes at: 1461658580998
Probing input buffer for format info...
Input: 33892 bytes at: 1461658581031
Input: 33312 bytes at: 1461658581065
Input: 33012 bytes at: 1461658581098
Input: 33724 bytes at: 1461658581131
Input: 33900 bytes at: 1461658581165
Input: 34272 bytes at: 1461658581198
Input: 33016 bytes at: 1461658581231
Input: 33612 bytes at: 1461658581265
Input: 33300 bytes at: 1461658581298
Input: 34348 bytes at: 1461658581331
Input: 34340 bytes at: 1461658581365
Input: 34268 bytes at: 1461658581398
Input: 33764 bytes at: 1461658581431
Input: 34008 bytes at: 1461658581464
Input: 33800 bytes at: 1461658581498
Input: 34504 bytes at: 1461658581531
Input: 33864 bytes at: 1461658581564
Input: 34600 bytes at: 1461658581598
Input: 34528 bytes at: 1461658581631
Input: 34516 bytes at: 1461658581664
Input: 35412 bytes at: 1461658581698
Input: 34676 bytes at: 1461658581731
Input: 34936 bytes at: 1461658581764
Input: 34548 bytes at: 1461658581798
Input: 34156 bytes at: 1461658581831
Input: 34256 bytes at: 1461658581864
Input: 33472 bytes at: 1461658581898
Input: 34264 bytes at: 1461658581931
Input: 33808 bytes at: 1461658581964
Input: 33868 bytes at: 1461658581998
Input: 101692 bytes at: 1461658582029
Input: 13188 bytes at: 1461658582064
Input: 244 bytes at: 1461658582097
Input: 936 bytes at: 1461658582130
Input: 5140 bytes at: 1461658582164
Input: 16340 bytes at: 1461658582197
Input: 43772 bytes at: 1461658582231
Input: 38212 bytes at: 1461658582264
Input: 36572 bytes at: 1461658582298
Input: 36184 bytes at: 1461658582331
Input: 36608 bytes at: 1461658582364
Input: 35452 bytes at: 1461658582398
Input: 35320 bytes at: 1461658582431
Input: 35088 bytes at: 1461658582464
Input: 34248 bytes at: 1461658582497
Input: 35396 bytes at: 1461658582531
Input: 35016 bytes at: 1461658582564
Input: 35368 bytes at: 1461658582597
Input: 34368 bytes at: 1461658582631
Input: 34492 bytes at: 1461658582664
Input: 35032 bytes at: 1461658582697
Input: 35036 bytes at: 1461658582731
Input: 34364 bytes at: 1461658582764
Input: 33140 bytes at: 1461658582797
Input: 33800 bytes at: 1461658582831
Input: 33888 bytes at: 1461658582864
Input: 33548 bytes at: 1461658582897
Input: 33196 bytes at: 1461658582931
Input: 33556 bytes at: 1461658582964
Input: 34600 bytes at: 1461658582997
Probing input buffer for format info...
Probing h264 score:51 size:2005772
Successfully acquired input format.
Input opened successfully!
Finding stream info...
[h264 @ 0x7fcd400008c0] Before avformat_find_stream_info() pos: 0 bytes
read:2005772 seeks:0
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
Input: [h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
34228 bytes at: 1461658583031
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] non-existing PPS 0 referenced
[h264 @ 0x7fcd400022a0] decode_slice_header error
[h264 @ 0x7fcd400022a0] no frame!
[h264 @ 0x7fcd400022a0] Current profile doesn't provide more RBSP data in
PPS, skipping
Input: 33400 bytes at: 1461658583064
[h264 @ 0x7fcd400008c0] 0: start_time: -9223372036854.775 duration:
-9223372036854.775
[h264 @ 0x7fcd400008c0] stream: start_time: -9223372036854.775 duration:
-9223372036854.775 bitrate=0 kb/s
[h264 @ 0x7fcd400008c0] After avformat_find_stream_info() pos: 2073400
bytes read:2073400 seeks:0 frames:62
Input #0, h264, from '(null)':
  Duration: N/A, bitrate: N/A
    Stream #0:0, 62, 1/1200000: Video: h264 (Main), 1 reference frame,
yuv420p(tv, left), 1920x1080 (1920x1088) [SAR 1:1 DAR 16:9], 1001/30000,
17.25 fps, 14.99 tbr, 1200k tbn, 29.97 tbc
Stream info acquired.
Finding codec...
Opening codec...
detected 8 logical cores
Codec opened.
Created output stream.
Copied input codec context to output codec context.
Writing FTYP+MOOV...
[mp4 @ 0x7fcd400010c0] Using AVStream.codec.time_base as a timebase hint to
the muxer is deprecated. Set AVStream.time_base instead.
Writing muxed packet. Bytes: 24
Writing muxed packet. Bytes: 754
Ready to mux!
Input: 33764 bytes at: 1461658583097
[mp4 @ 0x7fcd400010c0] Timestamps are unset in a packet for stream 0. This
is deprecated and will stop working in the future. Fix your code to set the
timestamps
properly

[mp4 @ 0x7fcd400010c0] Encoder did not produce proper pts, making some
up.
Writing muxed packet. Bytes: 33872
Input: 33804 bytes at: 1461658583131
Writing muxed packet. Bytes: 33912
Input: 34424 bytes at: 1461658583164
Writing muxed packet. Bytes: 34532
Input: 34152 bytes at: 1461658583197
Writing muxed packet. Bytes: 34260
Input: 34168 bytes at: 1461658583231
Writing muxed packet. Bytes: 34276
Input: 34072 bytes at: 1461658583264
Writing muxed packet. Bytes: 34180
Input: 33940 bytes at: 1461658583297
Writing muxed packet. Bytes: 34048
Input: 34448 bytes at: 1461658583331
Writing muxed packet. Bytes: 34556
Input: 33808 bytes at: 1461658583364
Writing muxed packet. Bytes: 33916
Input: 33916 bytes at: 1461658583397
Writing muxed packet. Bytes: 34024
Input: 34492 bytes at: 1461658583431
Writing muxed packet. Bytes: 34600
Input: 34384 bytes at: 1461658583464
Writing muxed packet. Bytes: 34492
Input: 33324 bytes at: 1461658583497
Writing muxed packet. Bytes: 33432
Input: 33184 bytes at: 1461658583530
Writing muxed packet. Bytes: 33292
Input: 33336 bytes at: 1461658583564
Writing muxed packet. Bytes: 33444
Input: 32800 bytes at: 1461658583597
Writing muxed packet. Bytes: 32908
Input: 32956 bytes at: 1461658583630
Writing muxed packet. Bytes: 33064
Input: 33092 bytes at: 1461658583664
Writing muxed packet. Bytes: 33200
Input: 32972 bytes at: 1461658583697
Writing muxed packet. Bytes: 33080
Input: 33516 bytes at: 1461658583730
Writing muxed packet. Bytes: 33624
Input: 33700 bytes at: 1461658583764
Writing muxed packet. Bytes: 33808
Input: 33836 bytes at: 1461658583797
Writing muxed packet. Bytes: 33944
Input: 34164 bytes at: 1461658583830
Writing muxed packet. Bytes: 34272
Input: 34460 bytes at: 1461658583864
Writing muxed packet. Bytes: 34568
Input: 34052 bytes at: 1461658583897
Writing muxed packet. Bytes: 34160
Input: 34072 bytes at: 1461658583930
Writing muxed packet. Bytes: 34180
Input: 34720 bytes at: 1461658583964
Writing muxed packet. Bytes: 34828
^C


Breaking this down, we save up a bunch of packets, attempt a probe, but it
fails. We save up some more frames and probe again. This time, the first 30
or so frames in the probe data buffer were associated with a PPS/SPS in the
previous discarded probeData buffer, so I believe that explains the first
stream of error messages. Eventually, it gets a new IDR-frame with a fresh
PPS/SPS and the probe is successful. The next bit brings me to my first
question:

[h264 @ 0x7fcd400008c0] 0: start_time: -9223372036854.775 duration:
-9223372036854.775
[h264 @ 0x7fcd400008c0] stream: start_time: -9223372036854.775 duration:
-9223372036854.775 bitrate=0 kb/s
[h264 @ 0x7fcd400008c0] After avformat_find_stream_info() pos: 2073400
bytes read:2073400 seeks:0 frames:62

Why are these time stamps and bitrate always garbage? Calling
av_dump_format on the input format context gives:

Input #0, h264, from '(null)':
  Duration: N/A, bitrate: N/A
    Stream #0:0, 62, 1/1200000: Video: h264 (Main), 1 reference frame,
yuv420p(tv, left), 1920x1080 (1920x1088) [SAR 1:1 DAR 16:9], 1001/30000,
17.25 fps, 14.99 tbr, 1200k tbn, 29.97 tbc

The FPS value here is weird, as it is a 30fps stream, as evidenced by my
callback timestamps (units in milliseconds). The TBC looks correct, but the
fps is way off, and the TBR is half of what I expect it to be. No idea
where the 1200k TBN came from. Here is the data contained in an SPS segment
of this stream. There is some timing information under the VUI section:


==================== NAL ====================

forbidden_zero_bit :0

nal_ref_idc :3

nal_unit_type : 7Sequence parameter set


======= SPS =======

profile_idc :77

constraint_set0_flag :0

constraint_set1_flag :1

constraint_set2_flag :0

constraint_set3_flag :0

constraint_set4_flag :0

constraint_set5_flag :0

reserved_zero_2bits :0

level_idc :31

seq_parameter_set_id :0

chroma_format_idc :1

residual_colour_transform_flag :0

bit_depth_luma_minus8 :0

bit_depth_chroma_minus8 :0

qpprime_y_zero_transform_bypass_flag :0

seq_scaling_matrix_present_flag :0

log2_max_frame_num_minus4 :0

pic_order_cnt_type :0

log2_max_pic_order_cnt_lsb_minus4 :6

delta_pic_order_always_zero_flag :0

offset_for_non_ref_pic :0

offset_for_top_to_bottom_field :0

num_ref_frames_in_pic_order_cnt_cycle :0

num_ref_frames :1

gaps_in_frame_num_value_allowed_flag :0

pic_width_in_mbs_minus1 :119

pic_height_in_map_units_minus1 :67

frame_mbs_only_flag :1

mb_adaptive_frame_field_flag :0

direct_8x8_inference_flag :1

frame_cropping_flag :1

frame_crop_left_offset :0

frame_crop_right_offset :0

frame_crop_top_offset :0

frame_crop_bottom_offset :4

vui_parameters_present_flag :1


=== VUI ===

aspect_ratio_info_present_flag :1

aspect_ratio_idc :1

sar_width :0

sar_height :0

overscan_info_present_flag :0

overscan_appropriate_flag :0

video_signal_type_present_flag :1

video_format :0

video_full_range_flag :0

colour_description_present_flag :0

colour_primaries :0

transfer_characteristics :0

matrix_coefficients :0

chroma_loc_info_present_flag :0

chroma_sample_loc_type_top_field :0

chroma_sample_loc_type_bottom_field :0

timing_info_present_flag :1

num_units_in_tick :6006

time_scale :180000

fixed_frame_rate_flag :0

nal_hrd_parameters_present_flag :1

vcl_hrd_parameters_present_flag :1

low_delay_hrd_flag :0

pic_struct_present_flag :0

bitstream_restriction_flag :0

motion_vectors_over_pic_boundaries_flag :0

max_bytes_per_pic_denom :0

max_bits_per_mb_denom :0

log2_max_mv_length_horizontal :0

log2_max_mv_length_vertical :0

num_reorder_frames :0

max_dec_frame_buffering :0


=== HRD ===

cpb_cnt_minus1 :0

bit_rate_scale :0

cpb_size_scale :0

bit_rate_value_minus1[0] :218749

cpb_size_value_minus1[0] :874999

cbr_flag[0] :0

initial_cpb_removal_delay_length_minus1 :31

cpb_removal_delay_length_minus1 :31

dpb_output_delay_length_minus1 :31

time_offset_length :24


The encoder goes on to give me a few more warnings, which I can only assume
are related to having bad timing info from the decode step.


In summary, does anyone know why this timing info might be so botched?
Additionally, is the logic employed in my code sound? There is very little
in the way of documentation/tutorials for working with raw streams from a
custom input buffer, and I haven't really found anyone else trying to mux
each frame like I have, so it is very possible that I've made many mistakes
(I'm surprised this works as well as it does).


Thanks,

Charles
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