lavc/avfft: deprecate the API

This deprecates the currently unused API.

doc/APIchanges

@@ -2,6 +2,11 @@ The last version increases of all libraries were on 2023-02-09
 
 API changes, most recent first:
 
+2023-09-xx - xxxxxxxxxx - lavc 60.25.100 - avfft.h
+  The entire header will be deprecated and removed in two major bumps.
+  For a replacement to av_dct, av_rdft, av_fft and av_mdct, use
+  the new API from libavutil/tx.h.
+
 2023-07-xx - xxxxxxxxxx - lavu 58.18.100 - tx.h
   Add AV_TX_REAL_TO_REAL and AV_TX_REAL_TO_IMAGINARY
 

libavcodec/avfft.h

@@ -19,6 +19,10 @@
 #ifndef AVCODEC_AVFFT_H
 #define AVCODEC_AVFFT_H
 
+#include "libavutil/attributes.h"
+#include "version_major.h"
+#if FF_API_AVFFT
+
 /**
  * @file
  * @ingroup lavc_fft
@@ -44,26 +48,42 @@ typedef struct FFTContext FFTContext;
  * Set up a complex FFT.
  * @param nbits           log2 of the length of the input array
  * @param inverse         if 0 perform the forward transform, if 1 perform the inverse
+ * @deprecated use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_FFT
  */
+attribute_deprecated
 FFTContext *av_fft_init(int nbits, int inverse);
 
 /**
  * Do the permutation needed BEFORE calling ff_fft_calc().
+ * @deprecated without replacement
  */
+attribute_deprecated
 void av_fft_permute(FFTContext *s, FFTComplex *z);
 
 /**
  * Do a complex FFT with the parameters defined in av_fft_init(). The
  * input data must be permuted before. No 1.0/sqrt(n) normalization is done.
+ * @deprecated use the av_tx_fn value returned by av_tx_init, which also does permutation
  */
+attribute_deprecated
 void av_fft_calc(FFTContext *s, FFTComplex *z);
 
+attribute_deprecated
 void av_fft_end(FFTContext *s);
 
+/**
+ * @deprecated use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_MDCT,
+ * with a flag of AV_TX_FULL_IMDCT for a replacement to av_imdct_calc.
+ */
+attribute_deprecated
 FFTContext *av_mdct_init(int nbits, int inverse, double scale);
+attribute_deprecated
 void av_imdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
+attribute_deprecated
 void av_imdct_half(FFTContext *s, FFTSample *output, const FFTSample *input);
+attribute_deprecated
 void av_mdct_calc(FFTContext *s, FFTSample *output, const FFTSample *input);
+attribute_deprecated
 void av_mdct_end(FFTContext *s);
 
 /* Real Discrete Fourier Transform */
@@ -81,9 +101,14 @@ typedef struct RDFTContext RDFTContext;
  * Set up a real FFT.
  * @param nbits           log2 of the length of the input array
  * @param trans           the type of transform
+ *
+ * @deprecated use av_tx_init from libavutil/tx.h with a type of AV_TX_FLOAT_RDFT
  */
+attribute_deprecated
 RDFTContext *av_rdft_init(int nbits, enum RDFTransformType trans);
+attribute_deprecated
 void av_rdft_calc(RDFTContext *s, FFTSample *data);
+attribute_deprecated
 void av_rdft_end(RDFTContext *s);
 
 /* Discrete Cosine Transform */
@@ -106,13 +131,19 @@ enum DCTTransformType {
  * @param type            the type of transform
  *
  * @note the first element of the input of DST-I is ignored
+ *
+ * @deprecated use av_tx_init from libavutil/tx.h with an appropriate type of AV_TX_FLOAT_DCT
  */
+attribute_deprecated
 DCTContext *av_dct_init(int nbits, enum DCTTransformType type);
+attribute_deprecated
 void av_dct_calc(DCTContext *s, FFTSample *data);
+attribute_deprecated
 void av_dct_end (DCTContext *s);
 
 /**
  * @}
  */
 
+#endif /* FF_API_AVFFT */
 #endif /* AVCODEC_AVFFT_H */

libavcodec/tests/fft.c

@@ -18,6 +18,10 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavutil/internal.h"
+
+FF_DISABLE_DEPRECATION_WARNINGS
+
 /**
  * @file
  * FFT and MDCT tests.
@@ -675,3 +679,5 @@ cleanup:
 
     return !!err;
 }
+
+FF_ENABLE_DEPRECATION_WARNINGS

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #include "version_major.h"
 
-#define LIBAVCODEC_VERSION_MINOR  24
+#define LIBAVCODEC_VERSION_MINOR  25
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \

libavcodec/version_major.h

@@ -50,6 +50,8 @@
 #define FF_API_TICKS_PER_FRAME     (LIBAVCODEC_VERSION_MAJOR < 61)
 #define FF_API_DROPCHANGED         (LIBAVCODEC_VERSION_MAJOR < 61)
 
+#define FF_API_AVFFT               (LIBAVCODEC_VERSION_MAJOR < 62)
+
 // reminder to remove CrystalHD decoders on next major bump
 #define FF_CODEC_CRYSTAL_HD        (LIBAVCODEC_VERSION_MAJOR < 61)