early-access version 1432

externals/ffmpeg/libavcodec/noise_bsf.c

@@ -0,0 +1,90 @@
+/*
+ * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <stdlib.h>
+
+#include "bsf.h"
+#include "bsf_internal.h"
+
+#include "libavutil/log.h"
+#include "libavutil/opt.h"
+
+typedef struct NoiseContext {
+    const AVClass *class;
+    int amount;
+    int dropamount;
+    unsigned int state;
+} NoiseContext;
+
+static int noise(AVBSFContext *ctx, AVPacket *pkt)
+{
+    NoiseContext *s = ctx->priv_data;
+    int amount = s->amount > 0 ? s->amount : (s->state % 10001 + 1);
+    int i, ret;
+
+    if (amount <= 0)
+        return AVERROR(EINVAL);
+
+    ret = ff_bsf_get_packet_ref(ctx, pkt);
+    if (ret < 0)
+        return ret;
+
+    if (s->dropamount > 0 && s->state % s->dropamount == 0) {
+        s->state++;
+        av_packet_unref(pkt);
+        return AVERROR(EAGAIN);
+    }
+
+    ret = av_packet_make_writable(pkt);
+    if (ret < 0) {
+        av_packet_unref(pkt);
+        return ret;
+    }
+
+    for (i = 0; i < pkt->size; i++) {
+        s->state += pkt->data[i] + 1;
+        if (s->state % amount == 0)
+            pkt->data[i] = s->state;
+    }
+
+    return 0;
+}
+
+#define OFFSET(x) offsetof(NoiseContext, x)
+#define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_BSF_PARAM)
+static const AVOption options[] = {
+    { "amount", NULL, OFFSET(amount), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
+    { "dropamount", NULL, OFFSET(dropamount), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
+    { NULL },
+};
+
+static const AVClass noise_class = {
+    .class_name = "noise",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+const AVBitStreamFilter ff_noise_bsf = {
+    .name           = "noise",
+    .priv_data_size = sizeof(NoiseContext),
+    .priv_class     = &noise_class,
+    .filter         = noise,
+};