[mythtv] Mythtranscode HLS/AVF heavily distorted output

[John Pilkington]

On 25/07/15 08:48, William Wilhelm wrote:
> Ever since 0.27 -> 0.28, mythtranscode --avf/--hls has been giving very
> distorted output for transcodings of FTA recordings here in Australia.
> Prebuilt "nightlies" from Mythbuntu and my own weekly builds from master
> both experience this issue. Audio is unaffected.
>
> All channels are affected except for ABC News 24 and SBS 2.
> To describe heavily distorted more: http://i.imgur.com/hfgrn2i.png.
>
> Here is mythffprobe output for an affected recording file before
> transcoding:
>
> ffprobe version v0.28-pre-2986-g004b87d Copyright (c) 2007-2014 the
> FFmpeg developers
>    built on Jul 25 2015 11:49:45 with gcc 4.9.2 (Gentoo 4.9.2 p1.0,
> pie-0.6.2)
>    configuration: --python=python2 --enable-libx264
>    libavutil      52. 92.100 / 52. 92.100
>    libavcodec     55. 69.100 / 55. 69.100
>    libavformat    55. 48.100 / 55. 48.100
>    libavdevice    55. 13.102 / 55. 13.102
>    libavfilter     4. 11.100 /  4. 11.100
>    libswscale      2.  6.100 /  2.  6.100
>    libswresample   0. 19.100 /  0. 19.100
>    libpostproc    52.  3.100 / 52.  3.100
> [mpegts @ 0x6a5020] write_section_data: PID 0x901 CRC error
> [mpegts @ 0x6a5020] write_section_data: PID 0x322 CRC error
> [mpegts @ 0x6a5020] write_section_data: PID 0x901 CRC error
> [mpegts @ 0x6a5020] write_section_data: PID 0x322 CRC error
> [NULL @ 0x6ab2a0] start time for stream 3 is not set in
> estimate_timings_from_pts
> [NULL @ 0x6acf80] start time for stream 4 is not set in
> estimate_timings_from_pts
> [mpegts @ 0x6a5020] write_section_data: PID 0x901 CRC error
> [mpegts @ 0x6a5020] PES packet size mismatch
> Input #0, mpegts, from 'fails2.ts':
>    Duration: 00:00:08.44, start: 95228.329600, bitrate: 4911 kb/s
>      Stream #0:0[0x205]: Video: mpeg2video (Main), yuv420p(tv), 720x576
> [SAR 64:45 DAR 16:9], max. 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc
>      Stream #0:1[0x2bc](eng): Audio: mp2, 48000 Hz, stereo, s16p, 192 kb/s
>      Stream #0:2[0x245](eng): Subtitle: dvb_teletext
>      Stream #0:3[0x901]: Data: dsmcc_b
>      Stream #0:4[0x322]: Data: dsmcc_b
> Unsupported codec with id 94215 for input stream 2
> Unsupported codec with id 1095979811 for input stream 3
> Unsupported codec with id 1095979811 for input stream 4
>
> Output for a non affected recording (from ABC News 24 or SBS 2) has
> similar output which I can provide if needed.
> Have several samples of affected and non-affected recordings that I can
> share.
>
> Thanks,
> Will

Have you tried doing a lossless transcode (-m) first?  It might discard 
all the streams that ffprobe dislikes.

John P