Evaluation procedure for 2015 audio watermark competition
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Documents
Host signals
- CD Tracks 27, 32, 35, 40, 65, 66, 69, and 70
- SQAM(SQAM_FLAC.zip;
EBU TECHNICAL)
Freely available.
- The initial and final segments of zero amplitude should be
removed from the audio clip shown above. Their new initial and final
samples are shown in the Table.
- They should be used repetitively for a duration of 60 s.
New initial and final samples to clip from each SQAM track.
SQAM no. | initial | final | repetition is required |
27 | 25390 | 726147 | yes |
32 | 24910 | 3145364 | no |
35 | 24904 | 2446802 | yes |
40 | 25302 | 2193536 | yes |
65 | 23937 | 4803885 | no |
66 | 22832 | 642775 | yes |
69 | 22888 | 1269672 | yes |
70 | 23365 | 733343 | yes |
Payload
Use the following data from the beginning bit. Error correction
schemes can be used to embed the payload of 90 bits per 15
seconds.
Supplementations to the contest
Series of a random sequence
- Error rate may somewhat depend on the random seed used to
randomize the start time of the stego signal for
detection. Therefore, the results of error rates should be
calculated as an arithmetic mean of 100 simulations with an
arbitrary random seed and random start time.
- The error rate of additive Gaussian noise may depend on a seed of
randomize. The simulation should be done as the above manner.
Objective evaluation of audio quality: PQevalAudio
- PQevalAudio
v2.0 (AFsp-v8r2.tar.gz; TSP lab. McGill Univ.)
- PQevalAudio requires audio files to be 48-kHz sampling.
The host signals must be converted from 44.1-kHz sampling to 48-kHz sampling using ResampAudio v5r1 which is included in AFsp-v8r2.
- PQevalAudio can not evaluate degradation of
single channel of sound quality for stereo signals. If the
embedding is conducted for single channel, ODGs have to be obtained
from monoaural signals of the signal channel to be embedded.
Frequency shift
Attack of sampling frequency conversion
- The sampling frequency conversion attack requires expansion and
contraction of duration and initial time for detection at the
same rate of conversion.
- For example, +10% conversion requires random selection from the
initial 16.5 seconds samples (a 10% increase from the original) of
the stego audio. Also, detection period is 49.5 seconds.
MPEG4AAC encoding and decoding
MP3 encoding and decoding
Bandpass filtering
A Series of The Attacks That Mimic DA And AD Conversions
The following signal processing steps mimic attacks using DA and AD
conversions.
Contact
-
Sending queries and reports for contest of audio watermarking.
-
About contest
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