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ffmpeg/libavformat/fifo.c

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/*
* FIFO pseudo-muxer
* Copyright (c) 2016 Jan Sebechlebsky
*
* 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 <stdatomic.h>
#include "libavutil/avassert.h"
#include "libavutil/opt.h"
#include "libavutil/time.h"
#include "libavutil/thread.h"
#include "libavutil/threadmessage.h"
#include "avformat.h"
#include "internal.h"
#include "mux.h"
#define FIFO_DEFAULT_QUEUE_SIZE 60
#define FIFO_DEFAULT_MAX_RECOVERY_ATTEMPTS 0
#define FIFO_DEFAULT_RECOVERY_WAIT_TIME_USEC 5000000 // 5 seconds
typedef struct FifoContext {
const AVClass *class;
AVFormatContext *avf;
char *format;
AVDictionary *format_options;
int queue_size;
AVThreadMessageQueue *queue;
pthread_t writer_thread;
/* Return value of last write_trailer_call */
int write_trailer_ret;
/* Time to wait before next recovery attempt
* This can refer to the time in processed stream,
* or real time. */
int64_t recovery_wait_time;
/* Maximal number of unsuccessful successive recovery attempts */
int max_recovery_attempts;
/* Whether to attempt recovery from failure */
int attempt_recovery;
/* If >0 stream time will be used when waiting
* for the recovery attempt instead of real time */
int recovery_wait_streamtime;
/* If >0 recovery will be attempted regardless of error code
* (except AVERROR_EXIT, so exit request is never ignored) */
int recover_any_error;
/* Whether to drop packets in case the queue is full. */
int drop_pkts_on_overflow;
/* Whether to wait for keyframe when recovering
* from failure or queue overflow */
int restart_with_keyframe;
pthread_mutex_t overflow_flag_lock;
int overflow_flag_lock_initialized;
/* Value > 0 signals queue overflow */
volatile uint8_t overflow_flag;
atomic_int_least64_t queue_duration;
int64_t last_sent_dts;
int64_t timeshift;
} FifoContext;
typedef struct FifoThreadContext {
AVFormatContext *avf;
/* Timestamp of last failure.
* This is either pts in case stream time is used,
* or microseconds as returned by av_getttime_relative() */
int64_t last_recovery_ts;
/* Number of current recovery process
* Value > 0 means we are in recovery process */
int recovery_nr;
/* If > 0 all frames will be dropped until keyframe is received */
uint8_t drop_until_keyframe;
/* Value > 0 means that the previous write_header call was successful
* so finalization by calling write_trailer and ff_io_close must be done
* before exiting / reinitialization of underlying muxer */
uint8_t header_written;
int64_t last_received_dts;
} FifoThreadContext;
typedef enum FifoMessageType {
FIFO_NOOP,
FIFO_WRITE_HEADER,
FIFO_WRITE_PACKET,
FIFO_FLUSH_OUTPUT
} FifoMessageType;
typedef struct FifoMessage {
FifoMessageType type;
AVPacket pkt;
} FifoMessage;
static int fifo_thread_write_header(FifoThreadContext *ctx)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
AVFormatContext *avf2 = fifo->avf;
AVDictionary *format_options = NULL;
int ret, i;
ret = av_dict_copy(&format_options, fifo->format_options, 0);
if (ret < 0)
goto end;
ret = ff_format_output_open(avf2, avf->url, &format_options);
if (ret < 0) {
av_log(avf, AV_LOG_ERROR, "Error opening %s: %s\n", avf->url,
av_err2str(ret));
goto end;
}
for (i = 0;i < avf2->nb_streams; i++)
ffstream(avf2->streams[i])->cur_dts = 0;
ret = avformat_write_header(avf2, &format_options);
if (!ret)
ctx->header_written = 1;
// Check for options unrecognized by underlying muxer
if (format_options) {
AVDictionaryEntry *entry = NULL;
while ((entry = av_dict_get(format_options, "", entry, AV_DICT_IGNORE_SUFFIX)))
av_log(avf2, AV_LOG_ERROR, "Unknown option '%s'\n", entry->key);
ret = AVERROR(EINVAL);
}
end:
av_dict_free(&format_options);
return ret;
}
static int fifo_thread_flush_output(FifoThreadContext *ctx)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
AVFormatContext *avf2 = fifo->avf;
return av_write_frame(avf2, NULL);
}
static int64_t next_duration(AVFormatContext *avf, AVPacket *pkt, int64_t *last_dts)
{
AVStream *st = avf->streams[pkt->stream_index];
int64_t dts = av_rescale_q(pkt->dts, st->time_base, AV_TIME_BASE_Q);
int64_t duration = (*last_dts == AV_NOPTS_VALUE ? 0 : dts - *last_dts);
*last_dts = dts;
return duration;
}
static int fifo_thread_write_packet(FifoThreadContext *ctx, AVPacket *pkt)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
AVFormatContext *avf2 = fifo->avf;
AVRational src_tb, dst_tb;
int ret, s_idx;
int64_t orig_pts, orig_dts, orig_duration;
if (fifo->timeshift && pkt->dts != AV_NOPTS_VALUE)
atomic_fetch_sub_explicit(&fifo->queue_duration, next_duration(avf, pkt, &ctx->last_received_dts), memory_order_relaxed);
if (ctx->drop_until_keyframe) {
if (pkt->flags & AV_PKT_FLAG_KEY) {
ctx->drop_until_keyframe = 0;
av_log(avf, AV_LOG_VERBOSE, "Keyframe received, recovering...\n");
} else {
av_log(avf, AV_LOG_VERBOSE, "Dropping non-keyframe packet\n");
av_packet_unref(pkt);
return 0;
}
}
orig_pts = pkt->pts;
orig_dts = pkt->dts;
orig_duration = pkt->duration;
s_idx = pkt->stream_index;
src_tb = avf->streams[s_idx]->time_base;
dst_tb = avf2->streams[s_idx]->time_base;
av_packet_rescale_ts(pkt, src_tb, dst_tb);
ret = av_write_frame(avf2, pkt);
if (ret >= 0) {
av_packet_unref(pkt);
} else {
// avoid scaling twice
pkt->pts = orig_pts;
pkt->dts = orig_dts;
pkt->duration = orig_duration;
}
return ret;
}
static int fifo_thread_write_trailer(FifoThreadContext *ctx)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
AVFormatContext *avf2 = fifo->avf;
int ret;
if (!ctx->header_written)
return 0;
ret = av_write_trailer(avf2);
ff_format_io_close(avf2, &avf2->pb);
return ret;
}
static int fifo_thread_dispatch_message(FifoThreadContext *ctx, FifoMessage *msg)
{
int ret = AVERROR(EINVAL);
if (msg->type == FIFO_NOOP)
return 0;
if (!ctx->header_written) {
ret = fifo_thread_write_header(ctx);
if (ret < 0)
return ret;
}
switch(msg->type) {
case FIFO_WRITE_HEADER:
av_assert0(ret >= 0);
return ret;
case FIFO_WRITE_PACKET:
return fifo_thread_write_packet(ctx, &msg->pkt);
case FIFO_FLUSH_OUTPUT:
return fifo_thread_flush_output(ctx);
}
av_assert0(0);
return AVERROR(EINVAL);
}
static int is_recoverable(const FifoContext *fifo, int err_no) {
if (!fifo->attempt_recovery)
return 0;
if (fifo->recover_any_error)
return err_no != AVERROR_EXIT;
switch (err_no) {
case AVERROR(EINVAL):
case AVERROR(ENOSYS):
case AVERROR_EOF:
case AVERROR_EXIT:
case AVERROR_PATCHWELCOME:
return 0;
default:
return 1;
}
}
static void free_message(void *msg)
{
FifoMessage *fifo_msg = msg;
if (fifo_msg->type == FIFO_WRITE_PACKET)
av_packet_unref(&fifo_msg->pkt);
}
static int fifo_thread_process_recovery_failure(FifoThreadContext *ctx, AVPacket *pkt,
int err_no)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
int ret;
av_log(avf, AV_LOG_INFO, "Recovery failed: %s\n",
av_err2str(err_no));
if (fifo->recovery_wait_streamtime) {
if (pkt->pts == AV_NOPTS_VALUE)
av_log(avf, AV_LOG_WARNING, "Packet does not contain presentation"
" timestamp, recovery will be attempted immediately");
ctx->last_recovery_ts = pkt->pts;
} else {
ctx->last_recovery_ts = av_gettime_relative();
}
if (fifo->max_recovery_attempts &&
ctx->recovery_nr >= fifo->max_recovery_attempts) {
av_log(avf, AV_LOG_ERROR,
"Maximal number of %d recovery attempts reached.\n",
fifo->max_recovery_attempts);
ret = err_no;
} else {
ret = AVERROR(EAGAIN);
}
return ret;
}
static int fifo_thread_attempt_recovery(FifoThreadContext *ctx, FifoMessage *msg, int err_no)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
AVPacket *pkt = &msg->pkt;
int64_t time_since_recovery;
int ret;
if (!is_recoverable(fifo, err_no)) {
ret = err_no;
goto fail;
}
if (ctx->header_written) {
fifo->write_trailer_ret = fifo_thread_write_trailer(ctx);
ctx->header_written = 0;
}
if (!ctx->recovery_nr) {
ctx->last_recovery_ts = fifo->recovery_wait_streamtime ?
AV_NOPTS_VALUE : 0;
} else {
if (fifo->recovery_wait_streamtime) {
if (ctx->last_recovery_ts == AV_NOPTS_VALUE) {
AVRational tb = avf->streams[pkt->stream_index]->time_base;
time_since_recovery = av_rescale_q(pkt->pts - ctx->last_recovery_ts,
tb, AV_TIME_BASE_Q);
} else {
/* Enforce recovery immediately */
time_since_recovery = fifo->recovery_wait_time;
}
} else {
time_since_recovery = av_gettime_relative() - ctx->last_recovery_ts;
}
if (time_since_recovery < fifo->recovery_wait_time)
return AVERROR(EAGAIN);
}
ctx->recovery_nr++;
if (fifo->max_recovery_attempts) {
av_log(avf, AV_LOG_VERBOSE, "Recovery attempt #%d/%d\n",
ctx->recovery_nr, fifo->max_recovery_attempts);
} else {
av_log(avf, AV_LOG_VERBOSE, "Recovery attempt #%d\n",
ctx->recovery_nr);
}
if (fifo->restart_with_keyframe && fifo->drop_pkts_on_overflow)
ctx->drop_until_keyframe = 1;
ret = fifo_thread_dispatch_message(ctx, msg);
if (ret < 0) {
if (is_recoverable(fifo, ret)) {
return fifo_thread_process_recovery_failure(ctx, pkt, ret);
} else {
goto fail;
}
} else {
av_log(avf, AV_LOG_INFO, "Recovery successful\n");
ctx->recovery_nr = 0;
}
return 0;
fail:
free_message(msg);
return ret;
}
static int fifo_thread_recover(FifoThreadContext *ctx, FifoMessage *msg, int err_no)
{
AVFormatContext *avf = ctx->avf;
FifoContext *fifo = avf->priv_data;
int ret;
do {
if (!fifo->recovery_wait_streamtime && ctx->recovery_nr > 0) {
int64_t time_since_recovery = av_gettime_relative() - ctx->last_recovery_ts;
int64_t time_to_wait = FFMAX(0, fifo->recovery_wait_time - time_since_recovery);
if (time_to_wait)
av_usleep(FFMIN(10000, time_to_wait));
}
ret = fifo_thread_attempt_recovery(ctx, msg, err_no);
} while (ret == AVERROR(EAGAIN) && !fifo->drop_pkts_on_overflow);
if (ret == AVERROR(EAGAIN) && fifo->drop_pkts_on_overflow) {
if (msg->type == FIFO_WRITE_PACKET)
av_packet_unref(&msg->pkt);
ret = 0;
}
return ret;
}
static void *fifo_consumer_thread(void *data)
{
AVFormatContext *avf = data;
FifoContext *fifo = avf->priv_data;
AVThreadMessageQueue *queue = fifo->queue;
FifoMessage msg = {fifo->timeshift ? FIFO_NOOP : FIFO_WRITE_HEADER, {0}};
int ret;
FifoThreadContext fifo_thread_ctx;
memset(&fifo_thread_ctx, 0, sizeof(FifoThreadContext));
fifo_thread_ctx.avf = avf;
fifo_thread_ctx.last_received_dts = AV_NOPTS_VALUE;
ff_thread_setname("fifo-consumer");
while (1) {
uint8_t just_flushed = 0;
if (!fifo_thread_ctx.recovery_nr)
ret = fifo_thread_dispatch_message(&fifo_thread_ctx, &msg);
if (ret < 0 || fifo_thread_ctx.recovery_nr > 0) {
int rec_ret = fifo_thread_recover(&fifo_thread_ctx, &msg, ret);
if (rec_ret < 0) {
av_thread_message_queue_set_err_send(queue, rec_ret);
break;
}
}
/* If the queue is full at the moment when fifo_write_packet
* attempts to insert new message (packet) to the queue,
* it sets the fifo->overflow_flag to 1 and drops packet.
* Here in consumer thread, the flag is checked and if it is
* set, the queue is flushed and flag cleared. */
pthread_mutex_lock(&fifo->overflow_flag_lock);
if (fifo->overflow_flag) {
av_thread_message_flush(queue);
if (fifo->restart_with_keyframe)
fifo_thread_ctx.drop_until_keyframe = 1;
fifo->overflow_flag = 0;
just_flushed = 1;
}
pthread_mutex_unlock(&fifo->overflow_flag_lock);
if (just_flushed)
av_log(avf, AV_LOG_INFO, "FIFO queue flushed\n");
if (fifo->timeshift)
while (atomic_load_explicit(&fifo->queue_duration, memory_order_relaxed) < fifo->timeshift)
av_usleep(10000);
ret = av_thread_message_queue_recv(queue, &msg, 0);
if (ret < 0) {
av_thread_message_queue_set_err_send(queue, ret);
break;
}
}
fifo->write_trailer_ret = fifo_thread_write_trailer(&fifo_thread_ctx);
return NULL;
}
static int fifo_mux_init(AVFormatContext *avf, const AVOutputFormat *oformat,
const char *filename)
{
FifoContext *fifo = avf->priv_data;
AVFormatContext *avf2;
int ret = 0, i;
ret = avformat_alloc_output_context2(&avf2, oformat, NULL, filename);
if (ret < 0)
return ret;
fifo->avf = avf2;
avf2->interrupt_callback = avf->interrupt_callback;
avf2->max_delay = avf->max_delay;
ret = av_dict_copy(&avf2->metadata, avf->metadata, 0);
if (ret < 0)
return ret;
avf2->opaque = avf->opaque;
avf2->io_close = avf->io_close;
avf2->io_close2 = avf->io_close2;
avf2->io_open = avf->io_open;
avf2->flags = avf->flags;
for (i = 0; i < avf->nb_streams; ++i) {
AVStream *st = ff_stream_clone(avf2, avf->streams[i]);
if (!st)
return AVERROR(ENOMEM);
}
return 0;
}
static int fifo_init(AVFormatContext *avf)
{
FifoContext *fifo = avf->priv_data;
const AVOutputFormat *oformat;
int ret = 0;
if (fifo->recovery_wait_streamtime && !fifo->drop_pkts_on_overflow) {
av_log(avf, AV_LOG_ERROR, "recovery_wait_streamtime can be turned on"
" only when drop_pkts_on_overflow is also turned on\n");
return AVERROR(EINVAL);
}
atomic_init(&fifo->queue_duration, 0);
fifo->last_sent_dts = AV_NOPTS_VALUE;
oformat = av_guess_format(fifo->format, avf->url, NULL);
if (!oformat) {
ret = AVERROR_MUXER_NOT_FOUND;
return ret;
}
ret = fifo_mux_init(avf, oformat, avf->url);
if (ret < 0)
return ret;
ret = av_thread_message_queue_alloc(&fifo->queue, (unsigned) fifo->queue_size,
sizeof(FifoMessage));
if (ret < 0)
return ret;
av_thread_message_queue_set_free_func(fifo->queue, free_message);
ret = pthread_mutex_init(&fifo->overflow_flag_lock, NULL);
if (ret < 0)
return AVERROR(ret);
fifo->overflow_flag_lock_initialized = 1;
return 0;
}
static int fifo_write_header(AVFormatContext *avf)
{
FifoContext * fifo = avf->priv_data;
int ret;
ret = pthread_create(&fifo->writer_thread, NULL, fifo_consumer_thread, avf);
if (ret) {
av_log(avf, AV_LOG_ERROR, "Failed to start thread: %s\n",
av_err2str(AVERROR(ret)));
ret = AVERROR(ret);
}
return ret;
}
static int fifo_write_packet(AVFormatContext *avf, AVPacket *pkt)
{
FifoContext *fifo = avf->priv_data;
FifoMessage msg = {.type = pkt ? FIFO_WRITE_PACKET : FIFO_FLUSH_OUTPUT};
int ret;
if (pkt) {
ret = av_packet_ref(&msg.pkt,pkt);
if (ret < 0)
return ret;
}
ret = av_thread_message_queue_send(fifo->queue, &msg,
fifo->drop_pkts_on_overflow ?
AV_THREAD_MESSAGE_NONBLOCK : 0);
if (ret == AVERROR(EAGAIN)) {
uint8_t overflow_set = 0;
/* Queue is full, set fifo->overflow_flag to 1
* to let consumer thread know the queue should
* be flushed. */
pthread_mutex_lock(&fifo->overflow_flag_lock);
if (!fifo->overflow_flag)
fifo->overflow_flag = overflow_set = 1;
pthread_mutex_unlock(&fifo->overflow_flag_lock);
if (overflow_set)
av_log(avf, AV_LOG_WARNING, "FIFO queue full\n");
ret = 0;
goto fail;
} else if (ret < 0) {
goto fail;
}
if (fifo->timeshift && pkt && pkt->dts != AV_NOPTS_VALUE)
atomic_fetch_add_explicit(&fifo->queue_duration, next_duration(avf, pkt, &fifo->last_sent_dts), memory_order_relaxed);
return ret;
fail:
if (pkt)
av_packet_unref(&msg.pkt);
return ret;
}
static int fifo_write_trailer(AVFormatContext *avf)
{
FifoContext *fifo= avf->priv_data;
int ret;
av_thread_message_queue_set_err_recv(fifo->queue, AVERROR_EOF);
if (fifo->timeshift) {
int64_t now = av_gettime_relative();
int64_t elapsed = 0;
FifoMessage msg = {FIFO_NOOP};
do {
int64_t delay = av_gettime_relative() - now;
if (delay < 0) { // Discontinuity?
delay = 10000;
now = av_gettime_relative();
} else {
now += delay;
}
atomic_fetch_add_explicit(&fifo->queue_duration, delay, memory_order_relaxed);
elapsed += delay;
if (elapsed > fifo->timeshift)
break;
av_usleep(10000);
ret = av_thread_message_queue_send(fifo->queue, &msg, AV_THREAD_MESSAGE_NONBLOCK);
} while (ret >= 0 || ret == AVERROR(EAGAIN));
atomic_store(&fifo->queue_duration, INT64_MAX);
}
ret = pthread_join(fifo->writer_thread, NULL);
if (ret < 0) {
av_log(avf, AV_LOG_ERROR, "pthread join error: %s\n",
av_err2str(AVERROR(ret)));
return AVERROR(ret);
}
ret = fifo->write_trailer_ret;
return ret;
}
static void fifo_deinit(AVFormatContext *avf)
{
FifoContext *fifo = avf->priv_data;
avformat_free_context(fifo->avf);
av_thread_message_queue_free(&fifo->queue);
if (fifo->overflow_flag_lock_initialized)
pthread_mutex_destroy(&fifo->overflow_flag_lock);
}
#define OFFSET(x) offsetof(FifoContext, x)
static const AVOption options[] = {
{"fifo_format", "Target muxer", OFFSET(format),
AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM},
{"queue_size", "Size of fifo queue", OFFSET(queue_size),
AV_OPT_TYPE_INT, {.i64 = FIFO_DEFAULT_QUEUE_SIZE}, 1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{"format_opts", "Options to be passed to underlying muxer", OFFSET(format_options),
AV_OPT_TYPE_DICT, {.str = NULL}, 0, 0, AV_OPT_FLAG_ENCODING_PARAM},
{"drop_pkts_on_overflow", "Drop packets on fifo queue overflow not to block encoder", OFFSET(drop_pkts_on_overflow),
AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{"restart_with_keyframe", "Wait for keyframe when restarting output", OFFSET(restart_with_keyframe),
AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{"attempt_recovery", "Attempt recovery in case of failure", OFFSET(attempt_recovery),
AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{"max_recovery_attempts", "Maximal number of recovery attempts", OFFSET(max_recovery_attempts),
AV_OPT_TYPE_INT, {.i64 = FIFO_DEFAULT_MAX_RECOVERY_ATTEMPTS}, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{"recovery_wait_time", "Waiting time between recovery attempts", OFFSET(recovery_wait_time),
AV_OPT_TYPE_DURATION, {.i64 = FIFO_DEFAULT_RECOVERY_WAIT_TIME_USEC}, 0, INT64_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{"recovery_wait_streamtime", "Use stream time instead of real time while waiting for recovery",
OFFSET(recovery_wait_streamtime), AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{"recover_any_error", "Attempt recovery regardless of type of the error", OFFSET(recover_any_error),
AV_OPT_TYPE_BOOL, {.i64 = 0}, 0, 1, AV_OPT_FLAG_ENCODING_PARAM},
{"timeshift", "Delay fifo output", OFFSET(timeshift),
AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, AV_OPT_FLAG_ENCODING_PARAM},
{NULL},
};
static const AVClass fifo_muxer_class = {
.class_name = "Fifo muxer",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const AVOutputFormat ff_fifo_muxer = {
.name = "fifo",
.long_name = NULL_IF_CONFIG_SMALL("FIFO queue pseudo-muxer"),
.priv_data_size = sizeof(FifoContext),
.init = fifo_init,
.write_header = fifo_write_header,
.write_packet = fifo_write_packet,
.write_trailer = fifo_write_trailer,
.deinit = fifo_deinit,
.priv_class = &fifo_muxer_class,
.flags = AVFMT_NOFILE | AVFMT_ALLOW_FLUSH | AVFMT_TS_NEGATIVE,
};
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