[FFmpeg-user] Compression is a lot smaller

[Cecil Westerhof]

Alexander Strasser <eclipse7 at gmx.net> writes:

> On 2020-08-15 16:25 +0200, Cecil Westerhof wrote:
>> Simon Roberts <simon at dancingcloudservices.com> writes:
>>
>> > On Sat, Aug 15, 2020 at 5:01 AM Cecil Westerhof <Cecil at decebal.nl> wrote:
>> >
>> >> Through scripts I use ffmpeg for cutting and compressing videos and
>> >> sometimes adding a watermark. Nothing fancy, but handy.
>> >>
>> >> In the past the original file was between 4 to 13 times bigger as the
>> >> compressed file. Today I compressed a few files again. The compression
>> >> was almost non existing to less as three.
>> >>
>> >
>> > [...]
>> >
>> >
>> >>
>> >
>> > What could be happening here?
>> >
>> >
>> > The most immediate thought is that zoom improved their compression
>> > algorithm and now there's not so much room left for a secondary
>> > improvement.
>> >
>> > You might want to take a look at the original, perhaps using ffprobe, to
>> > determine what codec was used, and what bitrate it started out with.
>>
>> No, that is not the case. These where videos I shot with my Sony
>> handycam. So uncompressed files.
>> But maybe I should have described it a bit clearer.
>
> Did I misread your logs?
>
> |    Input #0, mpegts, from '00039.MTS':
> |      Duration: 00:02:49.02, start: 1.040000, bitrate: 22533 kb/s
> |      Program 1
> |        Stream #0:0[0x1011]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p(top first), 1920x1080 [SAR 1:1 DAR 16:9],
> |+25 fps, 50 tbr, 90k tbn, 50 tbc
> |        Stream #0:1[0x1100]: Audio: ac3 (AC-3 / 0x332D4341), 48000 Hz, stereo, fltp, 256 kb/s
> |        Stream #0:2[0x1200]: Subtitle: hdmv_pgs_subtitle ([144][0][0][0] / 0x0090), 1920x1080
> |    Stream mapping:
> |      Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
>
> The input doesn't look uncompressed to me.

I do not have much knowledge of video formats, but this was really
shot with a Sony. Maybe that the Sony compresses the video itself?
It is a HDR-CX320.

-- 
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof