From 1aeedd277a6ecdf75b9478a61644e24370f82da2 Mon Sep 17 00:00:00 2001
From: Lynne <dev@lynne.ee>
Date: Sat, 5 Nov 2022 15:39:10 +0100
Subject: [PATCH] qdm2: convert to lavu/tx

---
 configure         |  2 +-
 libavcodec/qdm2.c | 46 ++++++++++++++++++++++++++--------------------
 2 files changed, 27 insertions(+), 21 deletions(-)

diff --git a/configure b/configure
index 52c61e62b2..3fa4d7065e 100755
--- a/configure
+++ b/configure
@@ -2920,7 +2920,7 @@ prores_encoder_select="fdctdsp"
 prores_aw_encoder_select="fdctdsp"
 prores_ks_encoder_select="fdctdsp"
 qcelp_decoder_select="lsp"
-qdm2_decoder_select="rdft mpegaudiodsp"
+qdm2_decoder_select="mpegaudiodsp"
 ra_144_decoder_select="audiodsp"
 ra_144_encoder_select="audio_frame_queue lpc audiodsp"
 ralf_decoder_select="golomb"
diff --git a/libavcodec/qdm2.c b/libavcodec/qdm2.c
index bdf7310b42..e629e3b42a 100644
--- a/libavcodec/qdm2.c
+++ b/libavcodec/qdm2.c
@@ -37,6 +37,7 @@
 #include "libavutil/channel_layout.h"
 #include "libavutil/mem_internal.h"
 #include "libavutil/thread.h"
+#include "libavutil/tx.h"
 
 #define BITSTREAM_READER_LE
 #include "avcodec.h"
@@ -46,7 +47,6 @@
 #include "decode.h"
 #include "mpegaudio.h"
 #include "mpegaudiodsp.h"
-#include "rdft.h"
 
 #include "qdm2_tablegen.h"
 
@@ -96,14 +96,9 @@ typedef struct QDM2SubPNode {
     struct QDM2SubPNode *next; ///< pointer to next packet in the list, NULL if leaf node
 } QDM2SubPNode;
 
-typedef struct QDM2Complex {
-    float re;
-    float im;
-} QDM2Complex;
-
 typedef struct FFTTone {
     float level;
-    QDM2Complex *complex;
+    AVComplexFloat *complex;
     const float *table;
     int   phase;
     int   phase_shift;
@@ -121,7 +116,8 @@ typedef struct FFTCoefficient {
 } FFTCoefficient;
 
 typedef struct QDM2FFT {
-    DECLARE_ALIGNED(32, QDM2Complex, complex)[MPA_MAX_CHANNELS][256];
+    DECLARE_ALIGNED(32, AVComplexFloat, complex)[MPA_MAX_CHANNELS][256 + 1];
+    DECLARE_ALIGNED(32, AVComplexFloat, temp)[MPA_MAX_CHANNELS][256];
 } QDM2FFT;
 
 /**
@@ -161,7 +157,8 @@ typedef struct QDM2Context {
     int fft_coefs_min_index[5];
     int fft_coefs_max_index[5];
     int fft_level_exp[6];
-    RDFTContext rdft_ctx;
+    AVTXContext *rdft_ctx;
+    av_tx_fn rdft_fn;
     QDM2FFT fft;
 
     /// I/O data
@@ -1428,7 +1425,7 @@ static void qdm2_fft_generate_tone(QDM2Context *q, FFTTone *tone)
 {
     float level, f[6];
     int i;
-    QDM2Complex c;
+    AVComplexFloat c;
     const double iscale = 2.0 * M_PI / 512.0;
 
     tone->phase += tone->phase_shift;
@@ -1476,7 +1473,7 @@ static void qdm2_fft_tone_synthesizer(QDM2Context *q, int sub_packet)
     const double iscale = 0.25 * M_PI;
 
     for (ch = 0; ch < q->channels; ch++) {
-        memset(q->fft.complex[ch], 0, q->fft_size * sizeof(QDM2Complex));
+        memset(q->fft.complex[ch], 0, q->fft_size * sizeof(AVComplexFloat));
     }
 
 
@@ -1484,7 +1481,7 @@ static void qdm2_fft_tone_synthesizer(QDM2Context *q, int sub_packet)
     if (q->fft_coefs_min_index[4] >= 0)
         for (i = q->fft_coefs_min_index[4]; i < q->fft_coefs_max_index[4]; i++) {
             float level;
-            QDM2Complex c;
+            AVComplexFloat c;
 
             if (q->fft_coefs[i].sub_packet != sub_packet)
                 break;
@@ -1545,14 +1542,19 @@ static void qdm2_calculate_fft(QDM2Context *q, int channel, int sub_packet)
 {
     const float gain = (q->channels == 1 && q->nb_channels == 2) ? 0.5f : 1.0f;
     float *out       = q->output_buffer + channel;
-    int i;
+
     q->fft.complex[channel][0].re *= 2.0f;
     q->fft.complex[channel][0].im  = 0.0f;
-    q->rdft_ctx.rdft_calc(&q->rdft_ctx, (FFTSample *)q->fft.complex[channel]);
+    q->fft.complex[channel][q->fft_size].re = 0.0f;
+    q->fft.complex[channel][q->fft_size].im = 0.0f;
+
+    q->rdft_fn(q->rdft_ctx, q->fft.temp[channel], q->fft.complex[channel],
+               sizeof(AVComplexFloat));
+
     /* add samples to output buffer */
-    for (i = 0; i < FFALIGN(q->fft_size, 8); i++) {
-        out[0]           += q->fft.complex[channel][i].re * gain;
-        out[q->channels] += q->fft.complex[channel][i].im * gain;
+    for (int i = 0; i < FFALIGN(q->fft_size, 8); i++) {
+        out[0]           += q->fft.temp[channel][i].re * gain;
+        out[q->channels] += q->fft.temp[channel][i].im * gain;
         out              += 2 * q->channels;
     }
 }
@@ -1613,7 +1615,8 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)
 {
     static AVOnce init_static_once = AV_ONCE_INIT;
     QDM2Context *s = avctx->priv_data;
-    int tmp_val, tmp, size;
+    int ret, tmp_val, tmp, size;
+    float scale = 1.0f / 2.0f;
     GetByteContext gb;
 
     /* extradata parsing
@@ -1756,7 +1759,10 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)
         return AVERROR_INVALIDDATA;
     }
 
-    ff_rdft_init(&s->rdft_ctx, s->fft_order, IDFT_C2R);
+    ret = av_tx_init(&s->rdft_ctx, &s->rdft_fn, AV_TX_FLOAT_RDFT, 1, 2*s->fft_size, &scale, 0);
+    if (ret < 0)
+        return ret;
+
     ff_mpadsp_init(&s->mpadsp);
 
     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
@@ -1770,7 +1776,7 @@ static av_cold int qdm2_decode_close(AVCodecContext *avctx)
 {
     QDM2Context *s = avctx->priv_data;
 
-    ff_rdft_end(&s->rdft_ctx);
+    av_tx_uninit(&s->rdft_ctx);
 
     return 0;
 }