AVCHD and best codec

8KMAX8KMAX Website User Posts: 184 Just Starting Out
edited February 25 in HitFilm

Hi,

Since my first camera, I have been using Mp4 media encoding. But I recently noticed some bad behaviour and extra weird compression using this format with my lumix fz300. It is known that AVCHD provides a higher quality and less compressed video, and I've found out that, indeed, AVCHD provides a better image. The problem comes when using hitfilm. Even with my 5Ghz intel I9-9900K and 2070 super, 64Gb ram, Nvme ssd.. footage is laggy and really slow to deal with. Is there a way to accelerate AVCDHD footage in hitfilm without using proxies or lowering down the quality?  I've heard about transcoding but don't know if it is worth it... Will I loose quality transcoding it to prores or similar? What format would you recommend me transcoding to? Will transcoding solve my problem?

Thanks.

Comments

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    I would disagree that it is known that AVCHD provides a higher quality and less compressed video. Less compressed translates to bitrate.

    Hmm, AVCHD is really no different than the "MP4" option provided on the same camera. In fact most cameras "MP4/MOV" is typically higher bitrate than AVCHD. This because they are not confined by the old AVCHD spec.  Most all MP4/MOV options in a camera are outputting AVC/H.264, which exactly what AVCHD is outputting. AVCHD tops out at 24-28Mbps. AVCHD does use AC3 audio (dolby digital), so that is a difference but that should decode as quickly as the audio codecs typically used in MP4/MOV containers. Anyway, I think Hitfilm is always using conformed audio and that result is PCM (simple and fast).

    As for performance the hardware decode in Hitfilm V12+ should handle the AVC with ease. Most any bitrate and profile. It would help to know your precise video specs. A MediaInfo text report would suffice. Even software decode should be fine with that CPU. Again precise specs are a help, as well as what it laggy. e.g. Everything even a simple video on a timeline (same frame size/rate specs) with play or just certain things.

  • 8KMAX8KMAX Website User Posts: 184 Just Starting Out

     "AVCHD is really no different than the "MP4" option provided on the same camera. In fact most cameras "MP4/MOV" is typically higher bitrate than AVCHD" 1080p mp4 video is 20Mbps, whereas 1080p AVCHD is 24Mbps. And the file size is double for AVCHD... The laggy problem occurs when playing back the video. That said, could transcoding solve the issue? What format should you recommend me transcoding to? As far as I know, it is believed that if you have mp4 footage and add effects, quality will be reduced each time a effect is added. It this true?

  • NormanPCNNormanPCN Website User Posts: 3,945 Enthusiast

    "1080p mp4 video is 20Mbps, whereas 1080p AVCHD is 24Mbps. And the file size is double for AVCHD"

    4Mbps is hardly anything all else being equal in the encode specs. The specs which we still do not know anything about. Double file size with a 20% change in video bitrate seems odd. As stated AVCHD uses AC3 audio but that is not much different than AAC which is typically used in MP4 containers. Audio is always much smaller than the video stream.

    "That said, could transcoding solve the issue?"

    Maybe, but you should not be having a problem with playback with AVCHD given what we know of your machine specs. So there may be something else going on that is slowing things down.

    "What format should you recommend me transcoding to?"

    Cineform would be good choice. Prores if you are on a Mac.

    "As far as I know, it is believed that if you have mp4 footage and add effects, quality will be reduced each time a effect is added. It this true?"

    No. First, there is no such thing as "MP4 footage". MP4 is just a generic container of a potential variety of video codecs (formats). That said most MP4 files tend to have AVC video, which as sated is exactly what AVCHD uses. Second, adding an effect does not reduce quality. An effect simply changes the frame in some way depending on the effect specifics. Once a frame is decoded from the video file it is simple RGB data. In other words, effects have no idea where/what a frame came from. If an effect reduces quality then it would do so on any/all video formats.

    You may be conflating re-encoding a video stream multiple times to a loss of quality. If you encode to a lossy format then there is some loss of quality. It may just be mathematical loss and not visual, but it is always there. So if you encode and then read the file back in and the  encode again, you are losing quality.

    If encoding and re-editing the result is something you need/desire then you those encodes those via an intermediate video codec (Cineform, Prores). These are lossy but high bitrate and high quality and hold up very well to numerous re-encodes. One can encode such intermediates to a lossless format but this results in quite massive files.

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