no audio stream and huge file sizes
 

Hi

I am currently using the Cineform Hd Link to convert 1920 by 1080 50i (pal land) at 25 fps in to Avi format to then edit in Sony Vegas Pro 9. I am using a sony nx5 cam to shoot the footage.

The first question i have is

1. It converts the footage perfectly but it does not find an audio stream from the files. This happens from the raw files on the sdhc card direct from the camera and also when the footage was first put through the sony content management utility?

2. Will i be able to convert raw files stright from the sdhc card and start editing?

3 I have noticed the file sizes are huge. After converting a file that was 258MB the converted file was 1.45gig. Is this normal?

I also have been reading on dvinfo.net and found that nero caused problems. I have unstalled it since and rebooted but still no success.

Thanks

1. See Cineform Tech Blog Blog Archive Converting AVCHD Files to CineForm Intermediate ( NOTE about Audio: If you are not properly converting audio, you may not have an AC3 decoder installed. Many software packages install an AC3 decoder, but if not, you can get a free AC3 decoder here: Free-Codecs.com :: Download AC3 Filter 1.63b : AC3 Filter is a DirectShow filter for AC3 decoding. )

2.Yep

3. Yup my 10gb AVCHD file can turn into 30GB/40GB after its converted

That is not good news about the file sizes. I average 60gig per wedding and have two next week.
That could mean 500gig in a shot. Ouch!! I kinda just presumed Sony Vegas would install an ac3 Encoder with Vegas. It's such a shame avchd is such a pain to work with.
Thanks for the reply David

Niall,

Codecs like MPEG and AVCHD were never intended for post. They were intended for distribution (satellite, DVD, Internet for instance). Why? They are optimized to produce *good* quality video with small files. The emphasis on "good" was intentional.

Consumer camera guys then adopted the format to use for *good* quality cameras. But in no case when designing these formats did anybody ever intend for the formats to be used in post production. In fact there is a natural conflict. To get small files you need long GOPs (Groups of Pictures), and you usually kill chroma resolution (4:2:0). Long GOPs are very difficult to deal with in post production.

Quality lost during capture can never be recreated, so our goal is to maintain everything that was shot in camera, and all of our tools are focused in this direction. The reality is that you get to choose two of the following three variables but you can't have all three: a) fast performance; b) high-quality; c) small files. CineForm is optimized for professional post-production workflows and has chosen the first two - fast and high quality. Our "variable" is file size, which is bigger than AVCHD, but is still 6x to 10x smaller than uncompressed.

You can edit AVCHD (h.264) directly in many NLEs with their small file sizes, but it isn't fast - it's a "pain".

FYI I ran some tests comparing the same DD file converted to PCM by Vegas and TMPGEnc, both DD approved codecs, with same file converted by ac3filter. When I compared the PCM waveforms in Soundforge the Vegas and TMPGEnc waveforms looked identical but the AC3filter waveform was obviously different (not gain). I could not hear the difference but that is not a good measurement. I suggest you run your own tests.

EB