View Full Version : SA TiVo Encoder/Decoder Capabilities

05-26-2002, 02:20 AM
Hi. I own an HD212 upgraded to 80 hrs. I bought the TiVo for many reasons, 1 in particular was to archive all my favorite TV shows to SVCD and VCD. Last week I recorded the season finale of Alias. After nitpicking each frame during the opening sequence I noticed some blockiness during some of the high motion frames (the car exploding). I was going to change the bitrates TiVo uses to record in Best Quality, but wanted to throw this out there first.

What are the maximum bitrates my TiVo can encode (record) without burning out either the encoder or decoder chip or both? Or, I thought if the bitrates were set too high, TiVo may not be able to keep up. I figured if I recorded with higher bitrates, the blockiness should go away, or become much less noticeable. Space really isnít an issue; I can always add another drive.

Anyone have any comments? Has anyone tested this?

05-27-2002, 11:23 AM
Thinking about this, not done anything yet but I can't understand why the Tivo uses obscure compression rates. The chipsets for the MPEG are standards off the shelf Philips chips so why not encode at standard rates.

I am a bit surprised that you are getting blockiness if best quality is selected. I can't see any on mine.

06-19-2002, 09:33 PM
It's been surprising to me to find that very little info exists on this subject. Go over to the SA Tivo area and look at the 544x480 thread.

The only way I know of to change bitrates and resolutions is via TivoWeb's Resource Editor, which I only got running this week. But it appears that the Sony encoder chip (not a Philips) is capable of full D1 resolution and DVD bitrates. Whether it can do this in the context of the SA Tivo is not clear.

At any rate, you will note in TivoWeb that the SA Tivo is set up to encode at different bitrates & resolutions for each of the "Quality" settings, and for each of the "Input" types i.e. SAT is recorded at higher settings than CATV which is set higher than Antenna. Which makes sense to me, except I have Digital Cable & some channels might benefit from better settings such as SAT settings, and Analog channels can likely be recorded at lower (less storage reqd) settings.

So I am experimenting with all this myself & thinking for example of applying Standard DVD settings (which are for US D1 720x480 and 1/2 D1 352x480) and also VideoCD standard settings for res & bitrate. All to make encoding for CD or DVD burning that much easier & highest quality possible. There is still the issue of audio (not to DVD standard either) but I believe/expect there is less danger/time in transcoding this than the video streams.