From f477a3f5abc15a9ffa117cd53ca93237a4f4d58c Mon Sep 17 00:00:00 2001 From: Zhang Rui Date: Thu, 16 Jul 2015 15:04:42 +0800 Subject: avformat/async: support filling with a background thread. Signed-off-by: Michael Niedermayer --- libavformat/Makefile | 1 + libavformat/allformats.c | 1 + libavformat/async.c | 387 +++++++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 389 insertions(+) create mode 100644 libavformat/async.c (limited to 'libavformat') diff --git a/libavformat/Makefile b/libavformat/Makefile index 479361aed9..108b6a67a2 100644 --- a/libavformat/Makefile +++ b/libavformat/Makefile @@ -496,6 +496,7 @@ OBJS-$(CONFIG_LIBSSH_PROTOCOL) += libssh.o OBJS-$(CONFIG_LIBSMBCLIENT_PROTOCOL) += libsmbclient.o # protocols I/O +OBJS-$(CONFIG_ASYNC_PROTOCOL) += async.o OBJS-$(CONFIG_APPLEHTTP_PROTOCOL) += hlsproto.o OBJS-$(CONFIG_BLURAY_PROTOCOL) += bluray.o OBJS-$(CONFIG_CACHE_PROTOCOL) += cache.o diff --git a/libavformat/allformats.c b/libavformat/allformats.c index 2caa6b111b..181cb9e6e9 100644 --- a/libavformat/allformats.c +++ b/libavformat/allformats.c @@ -351,6 +351,7 @@ void av_register_all(void) /* protocols */ + REGISTER_PROTOCOL(ASYNC, async); REGISTER_PROTOCOL(BLURAY, bluray); REGISTER_PROTOCOL(CACHE, cache); REGISTER_PROTOCOL(CONCAT, concat); diff --git a/libavformat/async.c b/libavformat/async.c new file mode 100644 index 0000000000..0748309639 --- /dev/null +++ b/libavformat/async.c @@ -0,0 +1,387 @@ +/* + * Input async protocol. + * Copyright (c) 2015 Zhang Rui + * + * 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 + * + * Based on libavformat/cache.c by Michael Niedermayer + */ + + /** + * @TODO + * support timeout + * support backward short seek + * support work with concatdec, hls + */ + +#include "libavutil/avassert.h" +#include "libavutil/avstring.h" +#include "libavutil/error.h" +#include "libavutil/fifo.h" +#include "libavutil/log.h" +#include "libavutil/opt.h" +#include "url.h" +#include +#include + +#if HAVE_UNISTD_H +#include +#endif + +#define BUFFER_CAPACITY (4 * 1024 * 1024) +#define SHORT_SEEK_THRESHOLD (256 * 1024) + +typedef struct Context { + AVClass *class; + URLContext *inner; + + int seek_request; + size_t seek_pos; + int seek_whence; + int seek_completed; + int64_t seek_ret; + + int io_error; + int io_eof_reached; + + size_t logical_pos; + size_t logical_size; + AVFifoBuffer *fifo; + + pthread_cond_t cond_wakeup_main; + pthread_cond_t cond_wakeup_background; + pthread_mutex_t mutex; + pthread_t async_buffer_thread; + + int abort_request; + AVIOInterruptCB interrupt_callback; +} Context; + +static int async_interrupt_callback(void *arg) +{ + URLContext *h = arg; + Context *c = h->priv_data; + int ret = 0; + + if (c->interrupt_callback.callback) { + ret = c->interrupt_callback.callback(c->interrupt_callback.opaque); + if (!ret) + return ret; + } + + return c->abort_request; +} + +static void *async_buffer_task(void *arg) +{ + URLContext *h = arg; + Context *c = h->priv_data; + AVFifoBuffer *fifo = c->fifo; + int ret = 0; + + while (1) { + int fifo_space, to_copy; + + if (async_interrupt_callback(h)) { + c->io_eof_reached = 1; + c->io_error = AVERROR_EXIT; + break; + } + + if (c->seek_request) { + pthread_mutex_lock(&c->mutex); + + ret = ffurl_seek(c->inner, c->seek_pos, c->seek_whence); + if (ret < 0) { + c->io_eof_reached = 1; + c->io_error = ret; + } else { + c->io_eof_reached = 0; + c->io_error = 0; + } + + c->seek_completed = 1; + c->seek_ret = ret; + c->seek_request = 0; + + av_fifo_reset(fifo); + + pthread_cond_signal(&c->cond_wakeup_main); + pthread_mutex_unlock(&c->mutex); + continue; + } + + fifo_space = av_fifo_space(fifo); + if (c->io_eof_reached || fifo_space <= 0) { + pthread_mutex_lock(&c->mutex); + pthread_cond_signal(&c->cond_wakeup_main); + pthread_cond_wait(&c->cond_wakeup_background, &c->mutex); + pthread_mutex_unlock(&c->mutex); + continue; + } + + to_copy = FFMIN(4096, fifo_space); + ret = av_fifo_generic_write(fifo, c->inner, to_copy, (void *)ffurl_read); + if (ret <= 0) { + c->io_eof_reached = 1; + if (ret < 0) { + c->io_error = ret; + } + } + + pthread_mutex_lock(&c->mutex); + pthread_cond_signal(&c->cond_wakeup_main); + pthread_mutex_unlock(&c->mutex); + } + + return NULL; +} + +static int async_open(URLContext *h, const char *arg, int flags, AVDictionary **options) +{ + Context *c = h->priv_data; + int ret; + AVIOInterruptCB interrupt_callback = {.callback = async_interrupt_callback, .opaque = h}; + + av_strstart(arg, "async:", &arg); + + c->fifo = av_fifo_alloc(BUFFER_CAPACITY); + if (!c->fifo) { + ret = AVERROR(ENOMEM); + goto fifo_fail; + } + + /* wrap interrupt callback */ + c->interrupt_callback = h->interrupt_callback; + ret = ffurl_open(&c->inner, arg, flags, &interrupt_callback, options); + if (ret != 0) { + av_log(h, AV_LOG_ERROR, "ffurl_open failed : %s, %s\n", strerror(ret), arg); + goto url_fail; + } + + c->logical_size = ffurl_size(c->inner); + h->is_streamed = c->inner->is_streamed; + + ret = pthread_mutex_init(&c->mutex, NULL); + if (ret != 0) { + av_log(h, AV_LOG_ERROR, "pthread_mutex_init failed : %s\n", strerror(ret)); + goto mutex_fail; + } + + ret = pthread_cond_init(&c->cond_wakeup_main, NULL); + if (ret != 0) { + av_log(h, AV_LOG_ERROR, "pthread_cond_init failed : %s\n", strerror(ret)); + goto cond_wakeup_main_fail; + } + + ret = pthread_cond_init(&c->cond_wakeup_background, NULL); + if (ret != 0) { + av_log(h, AV_LOG_ERROR, "pthread_cond_init failed : %s\n", strerror(ret)); + goto cond_wakeup_background_fail; + } + + ret = pthread_create(&c->async_buffer_thread, NULL, async_buffer_task, h); + if (ret) { + av_log(h, AV_LOG_ERROR, "pthread_create failed : %s\n", strerror(ret)); + goto thread_fail; + } + + return 0; + +thread_fail: + pthread_cond_destroy(&c->cond_wakeup_background); +cond_wakeup_background_fail: + pthread_cond_destroy(&c->cond_wakeup_main); +cond_wakeup_main_fail: + pthread_mutex_destroy(&c->mutex); +mutex_fail: + ffurl_close(c->inner); +url_fail: + av_fifo_freep(&c->fifo); +fifo_fail: + return ret; +} + +static int async_close(URLContext *h) +{ + Context *c = h->priv_data; + int ret; + + pthread_mutex_lock(&c->mutex); + c->abort_request = 1; + pthread_cond_signal(&c->cond_wakeup_background); + pthread_mutex_unlock(&c->mutex); + + ret = pthread_join(c->async_buffer_thread, NULL); + if (ret != 0) + av_log(h, AV_LOG_ERROR, "pthread_join(): %s\n", strerror(ret)); + + pthread_cond_destroy(&c->cond_wakeup_background); + pthread_cond_destroy(&c->cond_wakeup_main); + pthread_mutex_destroy(&c->mutex); + ffurl_close(c->inner); + av_fifo_freep(&c->fifo); + + return 0; +} + +static int async_read_internal(URLContext *h, void *dest, int size, int read_complete, + void (*func)(void*, void*, int)) +{ + Context *c = h->priv_data; + AVFifoBuffer *fifo = c->fifo; + int to_read = size; + int ret = 0; + + pthread_mutex_lock(&c->mutex); + + while (to_read > 0) { + int fifo_size, to_copy; + if (async_interrupt_callback(h)) { + ret = AVERROR_EXIT; + break; + } + fifo_size = av_fifo_size(fifo); + to_copy = FFMIN(to_read, fifo_size); + if (to_copy > 0) { + av_fifo_generic_read(fifo, dest, to_copy, func); + if (!func) + dest = (uint8_t *)dest + to_copy; + c->logical_pos += to_copy; + to_read -= to_copy; + ret = size - to_read; + + if (to_read <= 0 || !read_complete) + break; + } else if (c->io_eof_reached) { + if (ret <= 0) + ret = AVERROR_EOF; + break; + } + pthread_cond_signal(&c->cond_wakeup_background); + pthread_cond_wait(&c->cond_wakeup_main, &c->mutex); + } + + pthread_cond_signal(&c->cond_wakeup_background); + pthread_mutex_unlock(&c->mutex); + + return ret; +} + +static int async_read(URLContext *h, unsigned char *buf, int size) +{ + return async_read_internal(h, buf, size, 0, NULL); +} + +static void fifo_do_not_copy_func(void* dest, void* src, int size) { + // do not copy +} + +static int64_t async_seek(URLContext *h, int64_t pos, int whence) +{ + Context *c = h->priv_data; + AVFifoBuffer *fifo = c->fifo; + int64_t ret; + int64_t new_logical_pos; + int fifo_size; + + if (whence == AVSEEK_SIZE) { + av_log(h, AV_LOG_TRACE, "async_seek: AVSEEK_SIZE: %"PRId64"\n", (int64_t)c->logical_size); + return c->logical_size; + } else if (whence == SEEK_CUR) { + av_log(h, AV_LOG_TRACE, "async_seek: %"PRId64"\n", pos); + new_logical_pos = pos + c->logical_pos; + } else if (whence == SEEK_SET){ + av_log(h, AV_LOG_TRACE, "async_seek: %"PRId64"\n", pos); + new_logical_pos = pos; + } else { + return AVERROR(EINVAL); + } + if (new_logical_pos < 0) + return AVERROR(EINVAL); + + fifo_size = av_fifo_size(fifo); + if (new_logical_pos == c->logical_pos) { + /* current position */ + return c->logical_pos; + } else if ((new_logical_pos > c->logical_pos) && + (new_logical_pos < (c->logical_pos + fifo_size + SHORT_SEEK_THRESHOLD))) { + /* fast seek */ + av_log(h, AV_LOG_TRACE, "async_seek: fask_seek %"PRId64" from %d dist:%d/%d\n", + new_logical_pos, (int)c->logical_pos, + (int)(new_logical_pos - c->logical_pos), fifo_size); + async_read_internal(h, NULL, new_logical_pos - c->logical_pos, 1, fifo_do_not_copy_func); + return c->logical_pos; + } else if (c->logical_size <= 0) { + /* can not seek */ + return AVERROR(EINVAL); + } else if (new_logical_pos > c->logical_size) { + /* beyond end */ + return AVERROR(EINVAL); + } + + pthread_mutex_lock(&c->mutex); + + c->seek_request = 1; + c->seek_pos = new_logical_pos; + c->seek_whence = SEEK_SET; + c->seek_completed = 0; + c->seek_ret = 0; + + while (1) { + if (async_interrupt_callback(h)) { + ret = AVERROR_EXIT; + break; + } + if (c->seek_completed) { + if (c->seek_ret >= 0) + c->logical_pos = c->seek_ret; + ret = c->seek_ret; + break; + } + pthread_cond_signal(&c->cond_wakeup_background); + pthread_cond_wait(&c->cond_wakeup_main, &c->mutex); + } + + pthread_mutex_unlock(&c->mutex); + + return ret; +} + +#define OFFSET(x) offsetof(Context, x) +#define D AV_OPT_FLAG_DECODING_PARAM + +static const AVOption options[] = { + {NULL}, +}; + +static const AVClass async_context_class = { + .class_name = "Async", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + +URLProtocol ff_async_protocol = { + .name = "async", + .url_open2 = async_open, + .url_read = async_read, + .url_seek = async_seek, + .url_close = async_close, + .priv_data_size = sizeof(Context), + .priv_data_class = &async_context_class, +}; -- cgit v1.2.3