fix: Remove VLA to support compilation with MSVC

9 files changed, 42 insertions, 23 deletions

diff --git a/Makefile b/Makefile
index b973201..3f99ca3 100644
--- a/Makefile
+++ b/Makefile
@@ -29,7 +29,7 @@ AS := $(if $(AS)=as,$(CC),$(AS))
 LD := $(if $(LD)=ld,$(CC),$(LD))
 
 CFLAGS := $(if $(DEBUG),-O0 -g,-O3)
-CFLAGS += -std=c11 -Wall -Wextra -Wdouble-promotion
+CFLAGS += -std=c11 -Wall -Wextra -Wdouble-promotion -Wvla
 
 
 #
diff --git a/include/lc3.h b/include/lc3.h
index db16e46..9e84ffb 100644
--- a/include/lc3.h
+++ b/include/lc3.h
@@ -126,13 +126,17 @@ extern "C" {
  * Limitations
  * - On the bitrate, in bps, of a stream
  * - On the size of the frames in bytes
+ * - On the number of samples by frames
  */
 
-#define LC3_MIN_BITRATE    16000
-#define LC3_MAX_BITRATE   320000
+#define LC3_MIN_BITRATE         16000
+#define LC3_MAX_BITRATE        320000
 
-#define LC3_MIN_FRAME_BYTES   20
-#define LC3_MAX_FRAME_BYTES  400
+#define LC3_MIN_FRAME_BYTES        20
+#define LC3_MAX_FRAME_BYTES       400
+
+#define LC3_MIN_FRAME_SAMPLES  __LC3_NS( 7500,  8000)
+#define LC3_MAX_FRAME_SAMPLES  __LC3_NS(10000, 48000)
 
 
 /**
diff --git a/src/common.h b/src/common.h
index 3184913..d60ad9e 100644
--- a/src/common.h
+++ b/src/common.h
@@ -110,6 +110,9 @@
 #define LC3_NE(dt, sr) \
     ( 20 * (3 + (dt)) * (1 + (sr)) )
 
+#define LC3_MAX_NS \
+    LC3_NS(LC3_DT_10M, LC3_SRATE_48K)
+
 #define LC3_MAX_NE \
     LC3_NE(LC3_DT_10M, LC3_SRATE_48K)
 
diff --git a/src/lc3.c b/src/lc3.c
index 439d4b5..6f54300 100644
--- a/src/lc3.c
+++ b/src/lc3.c
@@ -396,7 +396,7 @@ int lc3_encode(struct lc3_encoder *encoder, enum lc3_pcm_format fmt,
     /* --- Processing --- */
 
     struct side_data side;
-    uint16_t xq[LC3_NE(encoder->dt, encoder->sr)];
+    uint16_t xq[LC3_MAX_NE];
 
     load[fmt](encoder, pcm, stride);
 
diff --git a/src/ltpf.c b/src/ltpf.c
index 3d13c20..a0cb7ba 100644
--- a/src/ltpf.c
+++ b/src/ltpf.c
@@ -646,7 +646,7 @@ bool lc3_ltpf_analyse(
     bool pitch_present = detect_pitch(ltpf, x_6k4, n_6k4, &tc);
 
     if (pitch_present) {
-        int16_t u[n_12k8], v[n_12k8];
+        int16_t u[128], v[128];
 
         data->pitch_index = refine_pitch(x_12k8, n_12k8, tc, &pitch);
 
@@ -686,6 +686,17 @@ bool lc3_ltpf_analyse(
  * -------------------------------------------------------------------------- */
 
 /**
+ * Width of synthesis filter
+ */
+
+#define FILTER_WIDTH(sr) \
+  LC3_MAX(4, LC3_SRATE_KHZ(sr) / 4)
+
+#define MAX_FILTER_WIDTH \
+  FILTER_WIDTH(LC3_NUM_SRATE)
+
+
+/**
  * Synthesis filter template
  * xh, nh          History ring buffer of filtered samples
  * lag             Lag parameter in the ring buffer
@@ -701,7 +712,7 @@ LC3_HOT static inline void synthesize_template(
 {
     float g = (float)(fade <= 0);
     float g_incr = (float)((fade > 0) - (fade < 0)) / n;
-    float u[w];
+    float u[MAX_FILTER_WIDTH];
 
     /* --- Load previous samples --- */
 
@@ -749,6 +760,7 @@ LC3_HOT static inline void synthesize_template(
  * Synthesis filter for each samplerates (width of filter)
  */
 
+
 LC3_HOT static void synthesize_4(const float *xh, int nh, int lag,
     const float *x0, float *x, int n, const float *c, int fade)
 {
@@ -808,8 +820,8 @@ void lc3_ltpf_synthesize(enum lc3_dt dt, enum lc3_srate sr, int nbytes,
     int g_idx = LC3_MAX(nbits / 80, 3 + (int)sr) - (3 + sr);
     bool active = data && data->active && g_idx < 4;
 
-    int w = LC3_MAX(4, LC3_SRATE_KHZ(sr) / 4);
-    float c[2*w];
+    int w = FILTER_WIDTH(sr);
+    float c[2 * MAX_FILTER_WIDTH];
 
     for (int i = 0; i < w; i++) {
         float g = active ? 0.4f - 0.05f * g_idx : 0;
@@ -821,7 +833,7 @@ void lc3_ltpf_synthesize(enum lc3_dt dt, enum lc3_srate sr, int nbytes,
 
     int ns = LC3_NS(dt, sr);
     int nt = ns / (3 + dt);
-    float x0[w];
+    float x0[MAX_FILTER_WIDTH];
 
     if (active)
         memcpy(x0, x + nt-(w-1), (w-1) * sizeof(float));
diff --git a/src/mdct.c b/src/mdct.c
index 10f0956..41a4fa1 100644
--- a/src/mdct.c
+++ b/src/mdct.c
@@ -419,7 +419,7 @@ void lc3_mdct_forward(enum lc3_dt dt, enum lc3_srate sr,
     int nf = LC3_NS(dt, sr_dst);
     int ns = LC3_NS(dt, sr);
 
-    struct lc3_complex buffer[ns/2];
+    struct lc3_complex buffer[LC3_MAX_NS / 2];
     struct lc3_complex *z = (struct lc3_complex *)y;
     union { float *f; struct lc3_complex *z; } u = { .z = buffer };
 
@@ -440,7 +440,7 @@ void lc3_mdct_inverse(enum lc3_dt dt, enum lc3_srate sr,
     int nf = LC3_NS(dt, sr_src);
     int ns = LC3_NS(dt, sr);
 
-    struct lc3_complex buffer[ns/2];
+    struct lc3_complex buffer[LC3_MAX_NS / 2];
     struct lc3_complex *z = (struct lc3_complex *)y;
     union { float *f; struct lc3_complex *z; } u = { .z = buffer };
 
diff --git a/src/spec.c b/src/spec.c
index 7ecf43b..7b13578 100644
--- a/src/spec.c
+++ b/src/spec.c
@@ -51,7 +51,7 @@ LC3_HOT static int estimate_gain(
     int nbits_budget, float nbits_off, int g_off, bool *reset_off)
 {
     int ne = LC3_NE(dt, sr) >> 2;
-    int e[ne];
+    int e[LC3_MAX_NE];
 
     /* --- Energy (dB) by 4 MDCT blocks --- */
 
diff --git a/tools/dlc3.c b/tools/dlc3.c
index d94eb36..109615b 100644
--- a/tools/dlc3.c
+++ b/tools/dlc3.c
@@ -187,13 +187,13 @@ int main(int argc, char *argv[])
 
     /* --- Setup decoding --- */
 
+    uint8_t in[2 * LC3_MAX_FRAME_BYTES];
+    int8_t alignas(int32_t) pcm[2 * LC3_MAX_FRAME_SAMPLES*4];
+    lc3_decoder_t dec[2];
+
     int frame_samples = lc3_frame_samples(frame_us, pcm_srate_hz);
     int encode_samples = pcm_samples +
         lc3_delay_samples(frame_us, pcm_srate_hz);
-
-    lc3_decoder_t dec[nch];
-    uint8_t in[nch * LC3_MAX_FRAME_BYTES];
-    int8_t alignas(int32_t) pcm[nch * frame_samples * pcm_sbytes];
     enum lc3_pcm_format pcm_fmt =
         pcm_sbits == 24 ? LC3_PCM_FORMAT_S24_3LE : LC3_PCM_FORMAT_S16;
 
diff --git a/tools/elc3.c b/tools/elc3.c
index 0e85075..654fa7f 100644
--- a/tools/elc3.c
+++ b/tools/elc3.c
@@ -193,16 +193,16 @@ int main(int argc, char *argv[])
 
     /* --- Setup encoding --- */
 
+    int8_t alignas(int32_t) pcm[2 * LC3_MAX_FRAME_SAMPLES*4];
+    uint8_t out[2 * LC3_MAX_FRAME_BYTES];
+    lc3_encoder_t enc[2];
+
     int frame_bytes = lc3_frame_bytes(frame_us, p.bitrate / nch);
     int frame_samples = lc3_frame_samples(frame_us, srate_hz);
     int encode_samples = nsamples + lc3_delay_samples(frame_us, srate_hz);
-
-    lc3_encoder_t enc[nch];
-    int8_t alignas(int32_t) pcm[nch * frame_samples * pcm_sbytes];
     enum lc3_pcm_format pcm_fmt =
         pcm_sbytes == 32/8 ? LC3_PCM_FORMAT_S24 :
         pcm_sbytes == 24/8 ? LC3_PCM_FORMAT_S24_3LE : LC3_PCM_FORMAT_S16;
-    uint8_t out[nch][frame_bytes];
 
     for (int ich = 0; ich < nch; ich++)
         enc[ich] = lc3_setup_encoder(frame_us, enc_srate_hz, srate_hz,
@@ -236,7 +236,7 @@ int main(int argc, char *argv[])
         for (int ich = 0; ich < nch; ich++)
             lc3_encode(enc[ich],
                 pcm_fmt, pcm + ich * pcm_sbytes, nch,
-                frame_bytes, out[ich]);
+                frame_bytes, out + ich * frame_bytes);
 
         lc3bin_write_data(fp_out, out, nch, frame_bytes);
     }