compress.c: Get rid of min_gain.

Always use no amplification, i.e. 1 << pcd->conf->inertia_arg as
the minimal gain.

diff --git a/compress.c b/compress.c
index 579a6ab643e479eb55156bdd3280f0d246dcee54..a6c3d32a18990719f454c971a1ead2de46659e0e 100644 (file)
--- a/compress.c
+++ b/compress.c
@@ -26,8 +26,6 @@ struct private_compress_data {
        unsigned current_gain;
        /** Points to the configuration data for this instance of the compress filter. */
        struct compress_filter_args_info *conf;
-       /** Minimal admissible gain. */
-       unsigned min_gain;
        /** Maximal admissible gain. */
        unsigned max_gain;
        /** Number of samples already seen. */
@@ -65,15 +63,14 @@ static ssize_t compress(char *inbuf, size_t inbuf_len, struct filter_node *fn)
                *op++ = sample >= 0? adjusted_sample : -adjusted_sample;
                if (likely(++pcd->num_samples & mask))
                        continue;
+//             PARA_DEBUG_LOG("gain: %u, peak: %u\n", pcd->current_gain,
+//                     pcd->peak);
                if (pcd->peak < pcd->conf->target_level_arg) {
                        if (pcd->current_gain < pcd->max_gain)
                                pcd->current_gain++;
-               } else {
-                       if (pcd->current_gain > pcd->min_gain + 1)
-                               pcd->current_gain -= 2;
-               }
-               PARA_DEBUG_LOG("gain: %lu, peak: %d\n", pcd->current_gain,
-                       pcd->peak);
+               } else
+                       pcd->current_gain = PARA_MAX(pcd->current_gain - 2,
+                               1 << pcd->conf->inertia_arg);
                pcd->peak = 0;
        }
        fn->loaded += length;
@@ -104,7 +101,6 @@ static void open_compress(struct filter_node *fn)
        fn->bufsize = COMPRESS_CHUNK_SIZE;
        fn->buf = para_malloc(fn->bufsize);
        pcd->current_gain = 1 << pcd->conf->inertia_arg;
-       pcd->min_gain = 1 << (pcd->conf->inertia_arg - pcd->conf->aggressiveness_arg);
        pcd->max_gain = 1 << (pcd->conf->inertia_arg + pcd->conf->aggressiveness_arg);
 }