Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: AAC profiles and AAC support in Flash (Read 2939 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

AAC profiles and AAC support in Flash

Hello. What are all of the AAC profiles? What are the differences between them exactly? And, Shockwave Flash format (what Adobe Flash Player uses) supports which AAC profiles exactly? Also, is AAC-LC MPEG-4 or is it MPEG-2 as https://wiki.multimedia.cx/index.php/Advanced_Audio_Coding says?

Re: AAC profiles and AAC support in Flash

Reply #1 –
I found that major profiles are LC, HEv1, HEv2, and xHE; am I right? If yes, here are my questions:

1: Does HE-AAC v1/v2 work with SBR at lower sampling rates (8kHz, 11025Hz, 12kHz, 16kHz, 22050Hz, 24kHz) too? If yes, are they as efficient as at higher sampling rates at these sampling rates?

2: Does xHE-AAC work with enhanced SBR at lower sampling rates (8kHz, 11025Hz, 12kHz, 16kHz, 22050Hz, 24kHz) too? If yes, is it as efficient as at higher sampling rates at these sampling rates?

3: I found that the difference of HE-AAC v2 (from v1) is that it uses parametric stereo, right? If yes, does that mean HE-AAC v2 does not work with mono or has no difference from HE-AAC v1 when working with mono?

4: In HE-AAC v1, HE-AAC v2, and xHE-AAC; what are the bandwidths of the base signals for each bandwidth or bitrate-samplerate combinations?

5: And, Flash supports which of them exactly?
 

Re: AAC profiles and AAC support in Flash

Reply #6 –
Quote from: Klymins on
I couldn't understand that, can you explain AAC Main and AAC SSR to me? And, which encoders can encode them?

Maybe this thread could give you an idea. Anyway, AAC-Main is dead, as SSR, SLS, LD/ELD, LTP and other variants or extensions.

Re: AAC profiles and AAC support in Flash

Reply #7 –
Quote from: a.ok.in on
Quote from: Klymins on
I couldn't understand that, can you explain AAC Main and AAC SSR to me? And, which encoders can encode them?

Maybe this thread could give you an idea. Anyway, AAC-Main is dead, as SSR, SLS, LD/ELD, LTP and other variants or extensions.

Thanks.

Now, can anyone explain MPEG2 and MPEG4 to me?

Re: AAC profiles and AAC support in Flash

Reply #8 –
Quote from: Klymins on
can anyone explain MPEG2 and MPEG4 to me?
Let's see if I got it right:
MPEG-1: 1993, gave you (MP1 and) MP2 and MP3, a video format, and a container format later retro-named "Program stream"
MPEG-2: 1995 to 1998 (++), came up with AAC and extended MP1/2/3. For video: H263. And, the "Transport stream"
MPEG-4: 1999 ff, gave you a big partly-evolving monster with tentacles in all directions. Some of them still in use, some not (be it over being obsolete or never even going anywhere ...)

Re: AAC profiles and AAC support in Flash

Reply #9 –
Quote from: Porcus on
Quote from: Klymins on
can anyone explain MPEG2 and MPEG4 to me?
Let's see if I got it right:
MPEG-1: 1993, gave you (MP1 and) MP2 and MP3, a video format, and a container format later retro-named "Program stream"
MPEG-2: 1995 to 1998 (++), came up with AAC and extended MP1/2/3. For video: H263. And, the "Transport stream"
MPEG-4: 1999 ff, gave you a big partly-evolving monster with tentacles in all directions. Some of them still in use, some not (be it over being obsolete or never even going anywhere ...)

Thank you.

Re: AAC profiles and AAC support in Flash

Reply #10 –
Quote from: Porcus on
Quote from: Klymins on
can anyone explain MPEG2 and MPEG4 to me?
Let's see if I got it right:
MPEG-1: 1993, gave you (MP1 and) MP2 and MP3, a video format, and a container format later retro-named "Program stream"
MPEG-2: 1995 to 1998 (++), came up with AAC and extended MP1/2/3. For video: H263. And, the "Transport stream"
MPEG-4: 1999 ff, gave you a big partly-evolving monster with tentacles in all directions. Some of them still in use, some not (be it over being obsolete or never even going anywhere ...)
;)
Also there was MPEG-3 (merged into MPEG-2 standard) and we have MPEG-5 since 2020 (although actually no one uses it).

Re: AAC profiles and AAC support in Flash

Reply #11 –
Quote from: Klymins on
1: Does HE-AAC v1/v2 work with SBR at lower sampling rates (8kHz, 11025Hz, 12kHz, 16kHz, 22050Hz, 24kHz) too? If yes, are they as efficient as at higher sampling rates at these sampling rates?

2: Does xHE-AAC work with enhanced SBR at lower sampling rates (8kHz, 11025Hz, 12kHz, 16kHz, 22050Hz, 24kHz) too? If yes, is it as efficient as at higher sampling rates at these sampling rates?

Why nobody answered these questions?

I want to ask the same things with different words: What are the minimum sampling rates of HE-AAC, xHE-AAC, and xHE-AAC with SBR?

Re: AAC profiles and AAC support in Flash

Reply #12 –
Nobody answered because it's easy enough to test yourself - get an encoder and test.
TAPE LOADING ERROR

Re: AAC profiles and AAC support in Flash

Reply #14 –
Quote from: itisljar on
Nobody answered because it's easy enough to test yourself - get an encoder and test.

This method may give wrong results because there may be some sampling rates that are supported by the standard but not supported by the encoder.

Re: AAC profiles and AAC support in Flash

Reply #15 –
I don't think there's anything in the MPEG standard that forbids those low sample rates, but I also don't think they'd be very useful - which is why you probably won't find any encoders or decoders that support them.

Re: AAC profiles and AAC support in Flash

Reply #16 –
Quote from: Octocontrabass on
I don't think there's anything in the MPEG standard that forbids those low sample rates, but I also don't think they'd be very useful - which is why you probably won't find any encoders or decoders that support them.

Both FDK-AAC and qaac support all sampling rates with LC-AAC but at least one of them does not support SBR with a low-called sampling rate (I remember I made a test some time ago) and I can't understand why this is the case because I see no reason to don't support a sampling rate with SBR which is supported without SBR. I'm planning to make a test to see which encoder supports which sampling rates for HE-AAC (probably only FDK-AAC and qaac).

Re: AAC profiles and AAC support in Flash

Reply #17 –
Correction: I've tried only 11025Hz and it's multiplies with them yet.