filter-chain: move buffer resample to separate function

Fix the error paths.
Rename some variables around to make things clearer.

src/modules/module-filter-chain/builtin_plugin.c

@@ -31,6 +31,7 @@
 #endif
 
 #include <spa/utils/json.h>
+#include <spa/utils/result.h>
 #include <spa/support/cpu.h>
 #include <spa/plugins/audioconvert/resample.h>
 
@@ -540,6 +541,71 @@ static float *create_dirac(const char *filename, float gain, int delay, int offs
 	return samples;
 }
 
+static float *resample_buffer(float *samples, int *n_samples,
+		unsigned long in_rate, unsigned long out_rate, uint32_t quality)
+{
+	uint32_t in_len, out_len, total_out = 0;
+	int out_n_samples;
+	float *out_samples, *out_buf, *in_buf;
+	struct resample r;
+	int res;
+
+	spa_zero(r);
+	r.channels = 1;
+	r.i_rate = in_rate;
+	r.o_rate = out_rate;
+	r.cpu_flags = dsp_ops.cpu_flags;
+	r.quality = quality;
+	if ((res = resample_native_init(&r)) < 0) {
+		pw_log_error("resampling failed: %s", spa_strerror(res));
+		errno = -res;
+		return NULL;
+	}
+
+	out_n_samples = SPA_ROUND_UP(*n_samples * out_rate, in_rate) / in_rate;
+	out_samples = calloc(out_n_samples, sizeof(float));
+	if (out_samples == NULL)
+		goto error;
+
+	in_len = *n_samples;
+	in_buf = samples;
+	out_len = out_n_samples;
+	out_buf = out_samples;
+
+	pw_log_info("Resampling filter: rate: %lu => %lu, n_samples: %u => %u, q:%u",
+		    in_rate, out_rate, in_len, out_len, quality);
+
+	resample_process(&r, (void*)&in_buf, &in_len, (void*)&out_buf, &out_len);
+	pw_log_debug("resampled: %u -> %u samples", in_len, out_len);
+	total_out += out_len;
+
+	in_len = resample_delay(&r);
+	in_buf = calloc(in_len, sizeof(float));
+	if (in_buf == NULL)
+		goto error;
+
+	out_buf = out_samples + total_out;
+	out_len = out_n_samples - total_out;
+
+	pw_log_debug("flushing resampler: %u in %u out", in_len, out_len);
+	resample_process(&r, (void*)&in_buf, &in_len, (void*)&out_buf, &out_len);
+	pw_log_debug("flushed: %u -> %u samples", in_len, out_len);
+	total_out += out_len;
+
+	free(in_buf);
+	free(samples);
+	resample_free(&r);
+
+	*n_samples = total_out;
+	return out_samples;
+
+error:
+	resample_free(&r);
+	free(samples);
+	free(out_samples);
+	return NULL;
+}
+
 static void * convolver_instantiate(const struct fc_descriptor * Descriptor,
 		unsigned long SampleRate, int index, const char *config)
 {
@@ -642,47 +708,9 @@ static void * convolver_instantiate(const struct fc_descriptor * Descriptor,
 		rate = SampleRate;
 		samples = read_samples(filename, gain, delay, offset,
 				length, channel, &rate, &n_samples);
-		if (rate != SampleRate) {
+		if (rate != SampleRate)
-			float *in_buffer = samples;
+			samples = resample_buffer(samples, &n_samples,
-			uint32_t in_len = n_samples;
+					rate, SampleRate, resample_quality);
-			uint32_t out_len = SPA_ROUND_UP(in_len * SampleRate, rate) / rate;
-			samples = calloc(out_len, sizeof(float));
-
-			pw_log_info(
-				"Resampling filter: rate: %lu => %lu, n_samples: %d => %d, q: %d",
-				    rate, SampleRate, n_samples, out_len, resample_quality
-			);
-
-			struct resample r;
-			spa_zero(r);
-			r.channels = 1;
-			r.i_rate = rate;
-			r.o_rate = SampleRate;
-			r.quality = resample_quality;
-			if (resample_native_init(&r) < 0) {
-				pw_log_error("resampling failed");
-				return NULL;
-			}
-
-			n_samples = out_len;
-			rate = SampleRate;
-
-			resample_process(&r, (void *)&in_buffer, &in_len, (void *)&samples, &out_len);
-			pw_log_debug("resampled: %u samples out", out_len);
-
-			free(in_buffer);
-
-			in_len = resample_delay(&r);
-			in_buffer = calloc(in_len, sizeof(float));
-
-			void *out_padded = samples + out_len;
-			out_len = n_samples - out_len; // Available space in buffer
-			pw_log_debug("flushing resampler: %u in %u out", in_len, out_len);
-			resample_process(&r, (void *)&in_buffer, &in_len, &out_padded, &out_len);
-
-			free(in_buffer);
-			r.free(&r);
-		}
 	}
 	if (samples == NULL) {
 		errno = ENOENT;