[FFmpeg-devel] Problem in opening trp ("special" MPEG-TS files)

Yiu-Chung Lee lee_yiu_chung
Fri Jun 20 17:34:44 CEST 2008

Dear all,

I live in Hong Kong where deploys digital terrestrial TV recently. I 
just bought a digital TV set-top box with recording functions. But I 
found that I have some problems in transcoding the file recording by the 
set-top box.

Firstly, let me describe the broadcasting parameters being used in Hong 
Kong digital broadcasting.

Broadcasting standard: DMB-T/H (http://en.wikipedia.org/wiki/DMB-T/H)
Multiplexing: MPEG2-TS
Video: H.264/MPEG2 Video
Audio: MPEG-1 Audio Layer II/AC3
Subtitle: ETSI EN 300 743 (or dvbsub in ffmpeg terms)

As a test, I recorded a few programmes, but have difficulties to 
transcode them. I found that my set-top box records the TV programmes 
with trp format, which seems to be a MPEG2-TS file with PAT/PMT headers 
stripped off. As a result, the complete data streams contained in the 
trp file cannot be found without scanning the whole file. (Just my wild 
guess, since I am not familiar to codecs, and these are based my "google 
research", and trial-and-error.)

In the first file I tried, it seems that it is unable to detect the 
dvbsub stream, and incorrectly attempted to use liba52 to decode it as 

In the second file I tried, since the subtitles appears near the end of 
file only, ffmpeg just doesn't find the subtitles PID stream. (Normally 
there should be 5 streams (1 H.264 video + 2 AC3 audio + 2 subtitles), 
but only 3 of them are detected (only video + audio).

I would like to ask if ffmpeg can support these "special" MPEG2-TS 
files, and detects the subtitles correctly. If you need these video 
samples, I can upload to you, but since one the file is file size 
related issue, I cannot follow your instruction to crop down it, but 
instead I would need to upload 120MB file to you. If it is not OK, you 
can ask me, and I will try to arrange another method to you.

Yiu-Chung Lee

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