dca_lbr: convert to lavu/tx

Fully converts the DCA decoder to lavu/tx.

configure

@@ -2807,7 +2807,6 @@ comfortnoise_encoder_select="lpc"
 cook_decoder_select="audiodsp sinewin"
 cri_decoder_select="mjpeg_decoder"
 cscd_decoder_suggest="zlib"
-dca_decoder_select="mdct"
 dca_encoder_select="mdct"
 dds_decoder_select="texturedsp"
 dirac_decoder_select="dirac_parse dwt golomb videodsp mpegvideoenc"

libavcodec/dca_lbr.c

@@ -953,12 +953,14 @@ static int parse_ts2_chunk(DCALbrDecoder *s, LBRChunk *chunk, int ch1, int ch2)
 static int init_sample_rate(DCALbrDecoder *s)
 {
     double scale = (-1.0 / (1 << 17)) * sqrt(1 << (2 - s->limited_range));
+    float scale_t = scale;
     int i, br_per_ch = s->bit_rate_scaled / s->nchannels_total;
     int ret;
 
-    ff_mdct_end(&s->imdct);
+    av_tx_uninit(&s->imdct);
 
-    ret = ff_mdct_init(&s->imdct, s->freq_range + 6, 1, scale);
+    ret = av_tx_init(&s->imdct, &s->imdct_fn, AV_TX_FLOAT_MDCT, 1,
+                     1 << (s->freq_range + 5), &scale_t, AV_TX_FULL_IMDCT);
     if (ret < 0)
         return ret;
 
@@ -1714,7 +1716,7 @@ static void transform_channel(DCALbrDecoder *s, int ch, float *output)
 
         base_func_synth(s, ch, values[0], sf);
 
-        s->imdct.imdct_calc(&s->imdct, result[0], values[0]);
+        s->imdct_fn(s->imdct, result[0], values[0], sizeof(float));
 
         // Long window and overlap-add
         s->fdsp->vector_fmul_add(output, result[0], s->window,
@@ -1834,5 +1836,5 @@ av_cold void ff_dca_lbr_close(DCALbrDecoder *s)
     s->ts_size = 0;
 
     av_freep(&s->fdsp);
-    ff_mdct_end(&s->imdct);
+    av_tx_uninit(&s->imdct);
 }

libavcodec/dca_lbr.h

@@ -23,13 +23,13 @@
 
 #include "libavutil/float_dsp.h"
 #include "libavutil/mem_internal.h"
+#include "libavutil/tx.h"
 
 #include "avcodec.h"
 #include "get_bits.h"
 #include "dca.h"
 #include "dca_exss.h"
 #include "dcadsp.h"
-#include "fft.h"
 
 #define DCA_LBR_CHANNELS        6
 #define DCA_LBR_CHANNELS_TOTAL  32
@@ -119,7 +119,8 @@ typedef struct DCALbrDecoder {
     DCALbrTone  tones[DCA_LBR_TONES];   ///< Circular buffer of tones
     int         ntones;                 ///< Circular buffer head position
 
-    FFTContext          imdct;
+    AVTXContext         *imdct;
+    av_tx_fn             imdct_fn;
     AVFloatDSPContext   *fdsp;
     DCADSPContext       *dcadsp;
 } DCALbrDecoder;