diff options
Diffstat (limited to 'libavutil')
-rw-r--r-- | libavutil/tx.h | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/libavutil/tx.h b/libavutil/tx.h index 53018c84e6..cacfd604d1 100644 --- a/libavutil/tx.h +++ b/libavutil/tx.h @@ -40,11 +40,17 @@ enum AVTXType { /** * Standard complex to complex FFT with sample data type AVComplexFloat. * Output is not 1/len normalized. Scaling currently unsupported. + * The stride parameter is ignored. */ AV_TX_FLOAT_FFT = 0, /** * Standard MDCT with sample data type of float and a scale type of * float. Length is the frame size, not the window size (which is 2x frame) + * For forward transforms, the stride specifies the spacing between each + * sample in the output array in bytes. The input must be a flat array. + * For inverse transforms, the stride specifies the spacing between each + * sample in the input array in bytes. The output will be a flat array. + * Stride must be a non-zero multiple of sizeof(float). */ AV_TX_FLOAT_MDCT = 1, /** @@ -53,6 +59,7 @@ enum AVTXType { AV_TX_DOUBLE_FFT = 2, /** * Same as AV_TX_FLOAT_MDCT with data and scale type of double. + * Stride must be a non-zero multiple of sizeof(double). */ AV_TX_DOUBLE_MDCT = 3, /** @@ -62,6 +69,7 @@ enum AVTXType { /** * Same as AV_TX_FLOAT_MDCT with data type of int32_t and scale type of float. * Only scale values less than or equal to 1.0 are supported. + * Stride must be a non-zero multiple of sizeof(int32_t). */ AV_TX_INT32_MDCT = 5, }; @@ -75,8 +83,11 @@ enum AVTXType { * @param s the transform context * @param out the output array * @param in the input array - * @param stride the input or output stride (depending on transform direction) - * in bytes, currently implemented for all MDCT transforms + * @param stride the input or output stride in bytes + * + * The out and in arrays must be aligned to the maximum required by the CPU + * architecture. + * The stride must follow the constraints the transform type has specified. */ typedef void (*av_tx_fn)(AVTXContext *s, void *out, void *in, ptrdiff_t stride); |