Do not add ID3 stream if output_id3_timestamps is disabled

[jeoliva]

Currently, no matter if vod_hls_output_id3_timestamps is enabled or not, the ID3 stream is always created in mpeg-ts segments of hls based outputs.

Given I have not seen any other use of the ID3 stream, but when vod_hls_output_id3_timestamps is enabled, and that I have found playback compatibility issues with older devices (smarttvs) when they find ID3 based streams in ts segments, I would like to propose create the ID3 stream just whenever it is going to be used.

[kaltura-hooks]

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[erankor]

Thank you for your patch.
This behavior was implemented intentionally - when we started this project, we migrated from another solution. That's how it was there, and we wanted to keep it to reduce risk.
To date, we haven't had any issues because of it, and therefore, I don't want to take this risk now.

[jeoliva]

In case it helps to you, or anyone having this same problem, we detected this problem on WebOS 2.0 based devices. They are not able to manage ID3 type of tracks/info. Even we needed to modify mpegts program descriptors (

nginx-vod-module/vod/hls/mpegts_encoder_filter.c

Line 70 in c907037

0x25, 0x0f, 0xff, 0xff, 0x49, 0x44, 0x33, 0x20, 0xff, 0x49,

) to don't include ID3 info.

Working like a charm after those changes.

If this is useful to you, I will push the program descriptor based changes.

[erankor]

If it's controlled by a conf param, I think we can merge it.
If you want to implement it -

1. I think it makes sense to add a new struct 'mpegts_encoder_conf_t' that will hold interleave_frames, align_frames and the new flag.
2. Please avoid pushing the trailing-space changes in the same pull. I didn't pay much attention to this in this project, maybe I'll find/replace it in all files... But either way, it will be in a dedicated pull without any other change.