diff options
Diffstat (limited to 'chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c')
| -rw-r--r-- | chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c | 18 |
1 files changed, 18 insertions, 0 deletions
diff --git a/chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c b/chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c index 0c453aee8e2..acdac042b6e 100644 --- a/chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c +++ b/chromium/third_party/ffmpeg/libavcodec/flacdsp_lpc_template.c @@ -139,3 +139,21 @@ static void FUNC(flac_lpc_encode_c)(int32_t *res, const int32_t *smp, int len, } #endif } + +/* Comment for clarity/de-obfuscation. + * + * for (int i = order; i < len; i++) { + * int32_t p = 0; + * for (int j = 0; j < order; j++) { + * int c = coefs[j]; + * int s = smp[(i-1)-j]; + * p += c*s; + * } + * res[i] = smp[i] - (p >> shift); + * } + * + * The CONFIG_SMALL code above simplifies to this, in the case of SAMPLE_SIZE + * not being equal to 32 (at the present time that means for 16-bit audio). The + * code above does 2 samples per iteration. Commit bfdd5bc ( made all the way + * back in 2007) says that way is faster. + */ |