212 lines
6.8 KiB
C
212 lines
6.8 KiB
C
/*
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* H.264 MP4 to Annex B byte stream format filter
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* Copyright (c) 2007 Benoit Fouet <benoit.fouet@free.fr>
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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 <string.h>
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#include "libavutil/intreadwrite.h"
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#include "libavutil/mem.h"
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#include "avcodec.h"
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typedef struct H264BSFContext {
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uint8_t length_size;
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uint8_t first_idr;
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int extradata_parsed;
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} H264BSFContext;
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static int alloc_and_copy(uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t *sps_pps, uint32_t sps_pps_size,
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const uint8_t *in, uint32_t in_size)
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{
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uint32_t offset = *poutbuf_size;
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uint8_t nal_header_size = offset ? 3 : 4;
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void *tmp;
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*poutbuf_size += sps_pps_size + in_size + nal_header_size;
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tmp = av_realloc(*poutbuf, *poutbuf_size + FF_INPUT_BUFFER_PADDING_SIZE);
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if (!tmp)
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return AVERROR(ENOMEM);
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*poutbuf = tmp;
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if (sps_pps)
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memcpy(*poutbuf + offset, sps_pps, sps_pps_size);
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memcpy(*poutbuf + sps_pps_size + nal_header_size + offset, in, in_size);
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if (!offset) {
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AV_WB32(*poutbuf + sps_pps_size, 1);
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} else {
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(*poutbuf + offset + sps_pps_size)[0] =
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(*poutbuf + offset + sps_pps_size)[1] = 0;
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(*poutbuf + offset + sps_pps_size)[2] = 1;
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}
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return 0;
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}
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static int h264_extradata_to_annexb(AVCodecContext *avctx, const int padding)
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{
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uint16_t unit_size;
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uint64_t total_size = 0;
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uint8_t *out = NULL, unit_nb, sps_done = 0,
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sps_seen = 0, pps_seen = 0;
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const uint8_t *extradata = avctx->extradata + 4;
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static const uint8_t nalu_header[4] = { 0, 0, 0, 1 };
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int length_size = (*extradata++ & 0x3) + 1; // retrieve length coded size
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/* retrieve sps and pps unit(s) */
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unit_nb = *extradata++ & 0x1f; /* number of sps unit(s) */
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if (!unit_nb) {
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goto pps;
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} else {
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sps_seen = 1;
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}
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while (unit_nb--) {
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void *tmp;
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unit_size = AV_RB16(extradata);
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total_size += unit_size + 4;
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if (total_size > INT_MAX - padding) {
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av_log(avctx, AV_LOG_ERROR,
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"Too big extradata size, corrupted stream or invalid MP4/AVCC bitstream\n");
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av_free(out);
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return AVERROR(EINVAL);
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}
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if (extradata + 2 + unit_size > avctx->extradata + avctx->extradata_size) {
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av_log(avctx, AV_LOG_ERROR, "Packet header is not contained in global extradata, "
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"corrupted stream or invalid MP4/AVCC bitstream\n");
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av_free(out);
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return AVERROR(EINVAL);
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}
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tmp = av_realloc(out, total_size + padding);
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if (!tmp) {
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av_free(out);
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return AVERROR(ENOMEM);
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}
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out = tmp;
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memcpy(out + total_size - unit_size - 4, nalu_header, 4);
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memcpy(out + total_size - unit_size, extradata + 2, unit_size);
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extradata += 2 + unit_size;
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pps:
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if (!unit_nb && !sps_done++) {
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unit_nb = *extradata++; /* number of pps unit(s) */
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if (unit_nb)
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pps_seen = 1;
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}
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}
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if (out)
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memset(out + total_size, 0, FF_INPUT_BUFFER_PADDING_SIZE);
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if (!sps_seen)
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av_log(avctx, AV_LOG_WARNING,
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"Warning: SPS NALU missing or invalid. "
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"The resulting stream may not play.\n");
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if (!pps_seen)
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av_log(avctx, AV_LOG_WARNING,
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"Warning: PPS NALU missing or invalid. "
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"The resulting stream may not play.\n");
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av_free(avctx->extradata);
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avctx->extradata = out;
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avctx->extradata_size = total_size;
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return length_size;
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}
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static int h264_mp4toannexb_filter(AVBitStreamFilterContext *bsfc,
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AVCodecContext *avctx, const char *args,
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uint8_t **poutbuf, int *poutbuf_size,
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const uint8_t *buf, int buf_size,
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int keyframe)
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{
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H264BSFContext *ctx = bsfc->priv_data;
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int i;
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uint8_t unit_type;
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int32_t nal_size;
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uint32_t cumul_size = 0;
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const uint8_t *buf_end = buf + buf_size;
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int ret = 0;
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/* nothing to filter */
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if (!avctx->extradata || avctx->extradata_size < 6) {
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*poutbuf = (uint8_t *)buf;
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*poutbuf_size = buf_size;
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return 0;
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}
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/* retrieve sps and pps NAL units from extradata */
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if (!ctx->extradata_parsed) {
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ret = h264_extradata_to_annexb(avctx, FF_INPUT_BUFFER_PADDING_SIZE);
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if (ret < 0)
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return ret;
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ctx->length_size = ret;
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ctx->first_idr = 1;
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ctx->extradata_parsed = 1;
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}
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*poutbuf_size = 0;
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*poutbuf = NULL;
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do {
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ret= AVERROR(EINVAL);
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if (buf + ctx->length_size > buf_end)
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goto fail;
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for (nal_size = 0, i = 0; i<ctx->length_size; i++)
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nal_size = (nal_size << 8) | buf[i];
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buf += ctx->length_size;
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unit_type = *buf & 0x1f;
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if (buf + nal_size > buf_end || nal_size < 0)
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goto fail;
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/* prepend only to the first type 5 NAL unit of an IDR picture */
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if (ctx->first_idr && unit_type == 5) {
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if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
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avctx->extradata, avctx->extradata_size,
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buf, nal_size)) < 0)
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goto fail;
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ctx->first_idr = 0;
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} else {
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if ((ret=alloc_and_copy(poutbuf, poutbuf_size,
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NULL, 0, buf, nal_size)) < 0)
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goto fail;
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if (!ctx->first_idr && unit_type == 1)
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ctx->first_idr = 1;
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}
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buf += nal_size;
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cumul_size += nal_size + ctx->length_size;
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} while (cumul_size < buf_size);
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return 1;
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fail:
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av_freep(poutbuf);
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*poutbuf_size = 0;
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return ret;
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}
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AVBitStreamFilter ff_h264_mp4toannexb_bsf = {
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.name = "h264_mp4toannexb",
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.priv_data_size = sizeof(H264BSFContext),
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.filter = h264_mp4toannexb_filter,
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};
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