topic Re: H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini in i.MX Processors

H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini

Hata-kun — Wed, 18 Nov 2020 02:35:14 GMT

I'm decoding H.264 TS file with GStreamer vpudec plug-in, but error message is generated and pipeline core dumped.

I ran the following pipeline:

GST_DEBUG=3 gst-launch-1.0 filesrc location=./h264.ts ! tsdemux ! vpudec ! fakesink

I got the following error:

root@ucm-imx8m-mini:/opt/tcr# GST_DEBUG=3 gst-launch-1.0 filesrc location=./h264.ts ! tsdemux ! vpudec ! fakesink Setting pipeline to PAUSED ... ====== VPUDEC: 4.4.4 build on Apr 23 2019 07:42:48. ====== wrapper: 3.0.0 (VPUWRAPPER_ARM64_LINUX Build on Apr 23 2019 06:54:11) vpulib: 1.1.1 firmware: 1.1.1.0 0:00:00.312292625 9942 0x688600 WARN basesrc gstbasesrc.c:3583:gst_base_src_start_complete:<filesrc0> pad not activated yet Pipeline is PREROLLING ... 0:00:00.355039625 9942 0x666cf0 FIXME videodecoder gstvideodecoder.c:933:gst_video_decoder_drain_out:<vpudec0> Sub-class should implement drain() 0:00:00.365649875 9942 0x666cf0 FIXME videodecoder gstvideodecoder.c:933:gst_video_decoder_drain_out:<vpudec0> Sub-class should implement drain() ERROR: ACCESS UNIT BOUNDARY CHECK 0:00:00.367152125 9942 0x666cf0 WARN vpu_dec_object gstvpudecobject.c:1461:gst_vpu_dec_object_decode:<vpudecobject0> Dropped video frame before VPU init ok! ERROR: ACCESS UNIT BOUNDARY CHECK 0:00:00.368643125 9942 0x666cf0 WARN vpu_dec_object gstvpudecobject.c:1461:gst_vpu_dec_object_decode:<vpudecobject0> Dropped video frame before VPU init ok! gst-launch-1.0: ../../source/h264high/legacy/h264hwd_stream.c:78: h264bsdGetBits: Assertion `num_bits < 32' failed. Aborted (core dumped)

I think cpb_removal_delay_length should be equal or less than 32,

is ASSERTION(num_bits <＝ 32) code right ?

This content is encoded with cpb_removal_delay_length as 32.

Re: H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini

igorpadykov — Wed, 18 Nov 2020 04:53:10 GMT

Hi Hata-kun

one can try

$ gst-launch-1.0 filesrc location=<filename.mp4> ! \
qtdemux name=d d.video_0 ! queue ! h264parse ! vpudec ! \
queue ! waylandsink

or examples from

https://community.nxp.com/t5/i-MX-Processors-Knowledge-Base/i-mx8M-EVK-board-encoder-and-decoder/ta-p/1116915

use i.MX8M Mini EVK with Demo Image from

https://www.nxp.com/design/software/embedded-software/i-mx-software/embedded-linux-for-i-mx-applications-processors:IMXLINUX

Best regards
igor

Re: H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini

Hata-kun — Wed, 18 Nov 2020 12:19:06 GMT

I tried changed pipeline, and got different error as follows.

root@ucm-imx8m-mini:/opt/tcr# GST_DEBUG=3 gst-launch-1.0 filesrc location=./h264.ts ! tsdemux name=d d.video_0 ! queue ! h264parse ! vpudec ! fakesink Setting pipeline to PAUSED ... ====== VPUDEC: 4.4.4 build on Apr 23 2019 07:42:48. ====== wrapper: 3.0.0 (VPUWRAPPER_ARM64_LINUX Build on Apr 23 2019 06:54:11) vpulib: 1.1.1 firmware: 1.1.1.0 0:00:00.074096750 2699 0x690b00 WARN basesrc gstbasesrc.c:3583:gst_base_src_start_complete:<filesrc0> pad not activated yet Pipeline is PREROLLING ... 0:00:00.077514250 2699 0x666e30 WARN default grammar.y:510:gst_parse_no_more_pads:<d> warning: Delayed linking failed. 0:00:00.077567000 2699 0x666e30 WARN default grammar.y:510:gst_parse_no_more_pads:<d> warning: failed delayed linking pad video_0 of GstTSDemux named d to some pad of GstQueue named queue0 WARNING: from element /GstPipeline:pipeline0/GstTSDemux:d: Delayed linking failed. Additional debug info: ../../../git/gst/parse/grammar.y(510): gst_parse_no_more_pads (): /GstPipeline:pipeline0/GstTSDemux:d: failed delayed linking pad video_0 of GstTSDemux named d to some pad of GstQueue named queue0 0:00:00.077983875 2699 0x666e30 WARN mpegtsbase mpegtsbase.c:1613:mpegts_base_loop:<d> error: Internal data stream error. 0:00:00.078029125 2699 0x666e30 WARN mpegtsbase mpegtsbase.c:1613:mpegts_base_loop:<d> error: streaming stopped, reason not-linked (-1) ERROR: from element /GstPipeline:pipeline0/GstTSDemux:d: Internal data stream error. Additional debug info: ../../../git/gst/mpegtsdemux/mpegtsbase.c(1613): mpegts_base_loop (): /GstPipeline:pipeline0/GstTSDemux:d: streaming stopped, reason not-linked (-1) ERROR: pipeline doesn't want to preroll. Setting pipeline to NULL ... Freeing pipeline ...

Re: H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini

igorpadykov — Wed, 18 Nov 2020 13:53:24 GMT

please try on i.MX8M Mini EVK with Demo Image

i.MX 8M Mini EVK

Best regards
igor

Re: H.264 decoding failed by Assertion `num_bits < 32' with GStreamer vpudec on i.MX8M-mini

Hata-kun — Tue, 15 Dec 2020 10:56:22 GMT

We had confirmed the problem was resolved by GStreamer 1.16.1 and VPU 4.5.5.

Thank you !