Chiebot-Mirror/FFmpeg - FFmpeg - Gitea: Git with a cup of tea

Author	SHA1	Message	Date
Claudio Freire	2a31b076b4	AAC encoder: fix assertion error with prediction Fixes an assertion error reported in #2686 that happens when using prediction (either explicitly or implicitly by setting the AAC main profile), since prediction code would allow creating new zeroes or removing existing ones, without properly checking for SF delta violations. This patch forbids creating/removing zeroes, perhaps an overly conservative approach, but a safe one. More permissive and sophisticated approaches may be attempted in the future.	9 years ago
Rostislav Pehlivanov	148cf4690c	aacenc_pred: only print predictor information if profile is aac_main Needed because LTP uses predictor_present as well.	9 years ago
Rostislav Pehlivanov	564db3e55d	aacenc_pred: correct header information	9 years ago
Rostislav Pehlivanov	93e6b23c9f	aacenc: shorten name of ff_aac_adjust_common_prediction To keep it similar to the other functions which are all named *_pred.	9 years ago
Claudio Freire	01ecb7172b	AAC encoder: Extensive improvements This finalizes merging of the work in the patches in ticket #2686. Improvements to twoloop and RC logic are extensive. The non-exhaustive list of twoloop improvments includes: - Tweaks to distortion limits on the RD optimization phase of twoloop - Deeper search in twoloop - PNS information marking to let twoloop decide when to use it (turned out having the decision made separately wasn't working) - Tonal band detection and priorization - Better band energy conservation rules - Strict hole avoidance For rate control: - Use psymodel's bit allocation to allow proper use of the bit reservoir. Don't work against the bit reservoir by moving lambda in the opposite direction when psymodel decides to allocate more/less bits to a frame. - Retry the encode if the effective rate lies outside a reasonable margin of psymodel's allocation or the selected ABR. - Log average lambda at the end. Useful info for everyone, but especially for tuning of the various encoder constants that relate to lambda feedback. Psy: - Do not apply lowpass with a FIR filter, instead just let the coder zero bands above the cutoff. The FIR filter induces group delay, and while zeroing bands causes ripple, it's lost in the quantization noise. - Experimental VBR bit allocation code - Tweak automatic lowpass filter threshold to maximize audio bandwidth at all bitrates while still providing acceptable, stable quality. I/S: - Phase decision fixes. Unrelated to #2686, but the bugs only surfaced when the merge was finalized. Measure I/S band energy accounting for phase, and prevent I/S and M/S from being applied both. PNS: - Avoid marking short bands with PNS when they're part of a window group in which there's a large variation of energy from one window to the next. PNS can't preserve those and the effect is extremely noticeable. M/S: - Implement BMLD protection similar to the specified in ISO-IEC/13818:7-2003, Appendix C Section 6.1. Since M/S decision doesn't conform to section 6.1, a different method had to be implemented, but should provide equivalent protection. - Move the decision logic closer to the method specified in ISO-IEC/13818:7-2003, Appendix C Section 6.1. Specifically, make sure M/S needs less bits than dual stereo. - Don't apply M/S in bands that are using I/S Now, this of course needed adjustments in the compare targets and fuzz factors of the AAC encoder's fate tests, but if wondering why the targets go up (more distortion), consider the previous coder was using too many bits on LF content (far more than required by psy), and thus those signals will now be more distorted, not less. The extra distortion isn't audible though, I carried extensive ABX testing to make sure. A very similar patch was also extensively tested by Kamendo2 in the context of #2686.	9 years ago
Rostislav Pehlivanov	8848c8440e	aacenc_pred: disable PNS SFBs and disable right predictors with IS Since PNS generates coefficients it doesn't make sense to send the predicted ones as well. Also the specifications explicitly state to disable right channel IS predictors. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>	9 years ago
Rostislav Pehlivanov	4565611b04	aacenc_is: add a flag to use pure coefficients instead This commit adds a flag to use the pure coefficients instead of the processed ones (sce->coeffs). This is needed because IS will apply the changes to the coefficients immediately before the adjust_common_prediction function and it doesn't make sense to measure stereo channel coefficient difference when one of the channels coefficients are all zero. Therefore add a flag to use pure coefficients in that case. TNS is the only thing touching the coefficients before IS so common window prediction will not take that into account but the effect of the TNS filter per coefficient can be small (a few percent) so to some approximation it's fine to just ignore that. Also fixed a small error which doesn't alter the results that much. pow(sqrt(number), 3.0/4.0) == pow(number, 3.0/8.0) != pow(number, 3.0/4.0). Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>	9 years ago
Rostislav Pehlivanov	44ddee945a	aacenc_pred: rework the way prediction is done This commit completely alters the algorithm of prediction. The original commit which introduced prediction was completely incorrect to even remotely care about what the actual coefficients contain or whether any options were enabled. Not my actual fault. This commit treats prediction the way the decoder does and expects to do: like lossy encryption. Everything related to prediction now happens at the very end but just before quantization and encoding of coefficients. On the decoder side, prediction happens before anything has had a chance to even access the coefficients. Also the original implementation had problems because it actually touched the band_type of special bands which already had their scalefactor indices marked and it's a wonder the asserion wasn't triggered when transmitting those. Overall, this now drastically increases audio quality and you should think about enabling it if you don't plan on playing anything encoded on really old low power ultra-embedded devices since they might not support decoding of prediction or AAC-Main. Though the specifications were written ages ago and as times change so do the FLOPS. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>	9 years ago
Timothy Gu	21dd5279c3	aacenc: Add missing ff_ prefixes Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com> Reviewed-by: Ganesh Ajjanagadde <gajjanag@mit.edu>	9 years ago
Rostislav Pehlivanov	76b81b10d9	aacenc: implement the complete AAC-Main profile This commit finalizes AAC-Main profile encoding support by implementing all mandatory and optional tools available in the specifications and current decoders. The AAC-Main profile reqires that prediction support be present (although decoders don't require it to be enabled) for an encoder to be deemed capable of AAC-Main encoding, as well as TNS, PNS and IS, all of which were implemented with previous commits or earlier of this year. Users are encouraged to test the new functionality using either -profile:a aac_main or -aac_pred 1, the former of which will enable the prediction option by default and the latter will change the profile to AAC-Main. No other options shall be changed by enabling either, it's currently up to the users to decide what's best. The current implementation works best using M/S and/or IS, so users are also welcome to enable both options and any other options (TNS, PNS) for maximum quality. Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>	9 years ago