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Ogg Format Accusations Refuted

SergeyKurdakov sends in a followup to our discussion a couple of months ago on purported shortcomings to the Ogg format. The inventor of the format, Monty "xiphmont" Montgomery of the Xiph Foundation, now refutes those objections in detail, with the introduction: "Earnest falsehoods left unchallenged risk being accepted as fact." The refutation has another advantage besides authoritativeness: it's far better written than the attack.

7 of 248 comments (clear)

  1. Re:Well written, and informative, but... by imsabbel · · Score: 5, Interesting

    Yeah.
    Also, for some reason there seems to exist no player in the world that can skip or jump in a video inside an OGM container without severe slowdowns and pauses even on an Core i7. Something that does simply not happen for avi, mp4, mkv or even mov (which is more or less mp4).

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  2. Re:Well written, and informative, but... by BikeHelmet · · Score: 4, Interesting

    I've noticed the same thing. MP4, MKV, AVI, etc. are instant, but ogv (ogm according to GSpot) has multi-second delays when seeking to specific parts of the video.

    I must be doing something wrong... and yet it's the same for every media player I try.

  3. Re:tl;dr by dgatwood · · Score: 4, Interesting

    What possible use could you have for obtaining time stamps within a video stream that you cannot decode? As far as I'm concerned, a container format should provide enough information to determine two things:

    1. A CODEC identifier (magic/FOURCC)
    2. The physical length of each frame's data so that decoders that don't understand a particular CODEC can skip it.

    Although there might be advantages of having other data encoded in a consistent fashion for people writing debug tools, when it comes to general software, as long as the CODEC software provides a standard set of accessor functions that return the data in a consistent way across all CODECs, it is by no means a requirement that they be stored in the same way, and in terms of the format's long-term flexibility, it is advantageous to allow the data to be stored in a codec-specific fashion.

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  4. Re:tl;dr by Rockoon · · Score: 3, Interesting

    As far as I'm concerned, a container format should provide enough information to determine two things:

    Basically, what you just wrote is "there shouldn't be containers."

    Is that really your position? I certainly can understand it. It has that quality to it that any hack can go ahead and start coding to handle it immediately, which is great. But checking with reality, we seem to have so many container formats because ID/LEN is just not enough for purposes.

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  5. Re:Well written, and informative, but... by evilviper · · Score: 4, Interesting

    And in any case, if you use a codec set to use few keyframes, you'll get poor seek performance in *any* container format - it's quite likely the issues you saw had everything to do with the encoding choices made and little with the (deprecated) ogm container.

    Not at all. Every other format listed as having good seek performance has an INDEX. Ogg/Ogm does not. Lacking an index generally results in broken frames when seeking as well.

    The are a couple efforts to get Ogg files indexed, but Xiph.org remains utterly indifferent, so you can expect it to remain an unsupported bastard step child like OGM, which is also only unofficial because Xiph can't be bothered with other people's needs.

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  6. Re:The goal by kiwieater · · Score: 4, Interesting

    I've always found Ogg/Vorbis to be superior to MP3. Using semi-good gear(electrostatic headphones, for the geeky folk), I find Ogg at q6(average of ~192kbps) to be nearer to CD quality than an MP3 at any bitrate - it's transparent in 95%+ of tracks.. Some music isn't transparent on either format regardless of bitrate, but Ogg has always tended to give better quality for a given filesize. All in my experience...

  7. Re:Ogg format considered not as good as MPEG by Haeleth · · Score: 4, Interesting

    VCD (created 1993) was massively popular in the second half of the nineties

    Really? I don't think I ever saw a single VCD on a store shelf. I recall they existed, and I think I even watched one once, but basically they were a brief fad that completely failed to make a measurable dent in the VHS market and rapidly disappeared without a trace. That's not what I'd call "massively popular".

    If you want to refute a rant, pick some illustrative points and clearly answer them.

    That is exactly the wrong thing to do. If you don't answer every point, then your opponents will simply pick out the points you omitted and claim that your failure to refute them proves that they are valid.

    Fancy colouring and highlighting don't make it better written.

    Who said they did? What makes it better-written is the higher quality of the prose. The supporting references and the real-world measurements help, too.