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

Author	SHA1	Message	Date
Ben Avison	5c22e8e4ad	armv6: Accelerate ff_imdct_half for general case (mdct_bits != 6) The previous implementation targeted DTS Coherent Acoustics, which only requires mdct_bits == 6. This relatively small size lent itself to unrolling the loops a small number of times, and encoding offsets calculated at assembly time within the load/store instructions of each iteration. In the more general case (codecs such as AAC and AC3) much larger arrays are used - mdct_bits == [8, 9, 11]. The old method does not scale for these cases, so more integer registers are used with non-unrolled versions of the loops (and with some stack spillage). The postrotation filter loop is still unrolled by a factor of 2 to permit the double-buffering of some VFP registers to facilitate overlap of neighbouring iterations. I benchmarked the result by measuring the number of gperftools samples that hit anywhere in the AAC decoder (starting from aac_decode_frame()) or specifically in ff_imdct_half_c / ff_imdct_half_vfp, for the same example AAC stream: Before After Mean StdDev Mean StdDev Confidence Change aac_decode_frame 2368.1 35.8 2117.2 35.3 100.0% +11.8% ff_imdct_half_* 457.5 22.4 251.2 16.2 100.0% +82.1% Signed-off-by: Martin Storsjö <martin@martin.st>	10 years ago
Ben Avison	42c1cc35b7	armv6: Accelerate ff_imdct_half for general case (mdct_bits != 6) The previous implementation targeted DTS Coherent Acoustics, which only requires mdct_bits == 6. This relatively small size lent itself to unrolling the loops a small number of times, and encoding offsets calculated at assembly time within the load/store instructions of each iteration. In the more general case (codecs such as AAC and AC3) much larger arrays are used - mdct_bits == [8, 9, 11]. The old method does not scale for these cases, so more integer registers are used with non-unrolled versions of the loops (and with some stack spillage). The postrotation filter loop is still unrolled by a factor of 2 to permit the double-buffering of some VFP registers to facilitate overlap of neighbouring iterations. I benchmarked the result by measuring the number of gperftools samples that hit anywhere in the AAC decoder (starting from aac_decode_frame()) or specifically in ff_imdct_half_c / ff_imdct_half_vfp, for the same example AAC stream: Before After Mean StdDev Mean StdDev Confidence Change aac_decode_frame 2368.1 35.8 2117.2 35.3 100.0% +11.8% ff_imdct_half_* 457.5 22.4 251.2 16.2 100.0% +82.1% Signed-off-by: Michael Niedermayer <michaelni@gmx.at>	10 years ago
Martin Storsjö	69e6702c01	arm: Mangle external symbols properly in new vfp assembly files Signed-off-by: Martin Storsjö <martin@martin.st>	11 years ago
Martin Storsjö	47d57f24e3	arm: Mangle external symbols properly in new vfp assembly files Reviewed-by: Kostya Shishkov Signed-off-by: Michael Niedermayer <michaelni@gmx.at>	11 years ago
Martin Storsjö	8b9eba664e	arm: Add VFP-accelerated version of fft16 Before After Mean StdDev Mean StdDev Change This function 1389.3 4.2 967.8 35.1 +43.6% Overall 15577.5 83.2 15400.0 336.4 +1.2% Signed-off-by: Martin Storsjö <martin@martin.st>	11 years ago
Martin Storsjö	b63bb251ea	arm: Add VFP-accelerated version of imdct_half Before After Mean StdDev Mean StdDev Change This function 2653.0 28.5 1108.8 51.4 +139.3% Overall 17049.5 408.2 15973.0 223.2 +6.7% Signed-off-by: Martin Storsjö <martin@martin.st>	11 years ago