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