[FFmpeg-user] Encoding multiple files for adaptive bit rate streaming using RTMP and HLS

Werner Robitza werner.robitza at gmail.com
Tue May 12 15:50:43 CEST 2015


On Tue, May 12, 2015 at 3:16 PM, Henk D. Schoneveld <belcampo at zonnet.nl> wrote:
>
>> On 12 May 2015, at 13:50, Werner Robitza <werner.robitza at gmail.com> wrote:
>>
>> On Tue, May 12, 2015 at 11:47 AM, Henk D. Schoneveld <belcampo at zonnet.nl> wrote:
>>> Would you be so kind to explain why to NOT use the crf option?
>>
>> CRF is essentially a constant quality mode, which results in variable
>> bitrate depending on the spatiotemporal complexity of the scenes.
> Your goal is max quality within a given link-capacity I assume.
> Upfront choosing an arbitrary bitrate to achieve max possible quality seems sub-optimal/contradictionary to me.
> A. to many bits for talking heads
> B. to few bits for action dominant events.

Yes, but that's still what's typically done, unless you choose a CQ
encoding type with a max-rate (which is what libvpx recommends too).

You should've mentioned that you're experienced with this -- otherwise
I would've given a different answer.

> I see the difference between the methods, but I don’t really understand what it’s trying to tel me. What does the X-axis say, total stream-size/#frames/ ?

It's the frame number (index) in a 3 minute sequence.


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