Why VLC display differently from sample_decode program for the same sample_encode output

[yu__leon]

Hi there,

I am trying the sample_encode and sample_decode programs from the Media SDK  2018 R1 API version 1.26 on windows 10

the input file for encoding can be played by a raw yuv player correctly. 

however I have two questions regarding to the generated encoding output file:

1.  when trying to play the encoding output file on VLC, it plays only part of the video contents. i.e. the video finishes before the full content as compared to the input yuv file.  However,  the sample_decode -r option does  render the full content  given the same encoding output file.

2. the sample_decode renders the video at a much higher frame rate compared to  raw yuv input.  i.e. if the input yuv file plays for 10 seconds, the sample_decode would complete the full video content in 3 seconds.  Is this expected? 

 Any advice is greatly appreciated. thank you.

here is the command prompt message for sample_encode and sample_decode programs

D:\MyProjects\IntelMediaSDK\samples\samples\_build\x64\Debug> .\sample_encode.exe -nv12 -tff -sw h264 -u speed -i "d:

\intelsdk_test\nv12.yuv" -o "d:\intelsdk_test\sample_encode.h264" -w 720 -h 576 -dump "d:\intelsdk_test\config.txt"

Encoding Sample Version 8.3.26.0

Input file format       NV12

Output video            AVC

Source picture:

        Resolution      720x576

        Crop X,Y,W,H    0,0,720,576

Destination picture:

        Resolution      720x576

        Crop X,Y,W,H    0,0,720,576

Frame rate      30.00

Bit rate(Kbps)  3000

Gop size        60

Ref dist        4

Ref number      0

Idr Interval    0

Target usage    speed

Memory type     system

Media SDK impl          sw

Media SDK version       1.26

Processing started

Frame number: 241

Encoding fps: 74

Processing finished

PS D:\MyProjects\IntelMediaSDK\samples\samples\_build\x64\Debug> .\sample_decode.exe h264 -sw -i "D:\intelsdk_test\sampl

e_encode.h264" -r

Decoding Sample Version 8.3.26.0

Input video     AVC

Output format   NV12

Input:

  Resolution    720x576

  Crop X,Y,W,H  0,0,0,0

Output:

  Resolution    720x576

Frame rate      30.00

Memory type             d3d

MediaSDK impl           sw

MediaSDK version        1.26

Decoding started

Frame number:  241, fps: 195.018, fread_fps: 0.000, fwrite_fps: 1723.559

Decoding finished

[Mark_L_Intel1]

Hi Leon,

#1. Media SDK uses the standard raw stream file to input the content which follows the video standard, VLS might have its own parser for the input file, the problem could happen in both side, but the current scenario can't tell me which one has the problem.

#2. Yes, this is expected since you got the full hardware speed. You can use "-f <framerate>" to get the normal rendering rate you expected.

Mark 

[yu__leon]

thanks for replying.   the encoded h.264 stream plays correctly after putting into mp4 container.