diff options
author | Michael Niedermayer <michaelni@gmx.at> | 2014-12-25 23:39:51 +0300 |
---|---|---|
committer | Michael Niedermayer <michaelni@gmx.at> | 2014-12-26 00:09:24 +0300 |
commit | 8706910c4c051dbc7377a702aff11424585d4778 (patch) | |
tree | 920b4b9f49d501170a2f8e7b86651459ac6536ca /libavformat/cache.c | |
parent | 7018d3d3510ee5be4fabd95b011373f9e826f897 (diff) |
avformat/cache: Support user specified read-ahead for non seekable media
Fixes Ticket2406
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
Diffstat (limited to 'libavformat/cache.c')
-rw-r--r-- | libavformat/cache.c | 42 |
1 files changed, 41 insertions, 1 deletions
diff --git a/libavformat/cache.c b/libavformat/cache.c index 48a342f0ec..0746e98d3e 100644 --- a/libavformat/cache.c +++ b/libavformat/cache.c @@ -30,6 +30,7 @@ #include "libavutil/avassert.h" #include "libavutil/avstring.h" #include "libavutil/file.h" +#include "libavutil/opt.h" #include "libavutil/tree.h" #include "avformat.h" #include <fcntl.h> @@ -51,6 +52,7 @@ typedef struct CacheEntry { } CacheEntry; typedef struct Context { + AVClass *class; int fd; struct AVTreeNode *root; int64_t logical_pos; @@ -60,6 +62,7 @@ typedef struct Context { int is_true_eof; URLContext *inner; int64_t cache_hit, cache_miss; + int read_ahead_limit; } Context; static int cmp(void *key, const void *node) @@ -214,6 +217,7 @@ static int64_t cache_seek(URLContext *h, int64_t pos, int whence) whence = SEEK_SET; pos += c->logical_pos; } else if (whence == SEEK_END && c->is_true_eof) { +resolve_eof: whence = SEEK_SET; pos += c->end; } @@ -226,6 +230,27 @@ static int64_t cache_seek(URLContext *h, int64_t pos, int whence) //cache miss ret= ffurl_seek(c->inner, pos, whence); + if ((whence == SEEK_SET && pos >= c->logical_pos || + whence == SEEK_END && pos <= 0) && ret < 0) { + if ( (whence == SEEK_SET && c->read_ahead_limit >= pos - c->logical_pos) + || c->read_ahead_limit < 0) { + uint8_t tmp[32768]; + while (c->logical_pos < pos || whence == SEEK_END) { + int size = sizeof(tmp); + if (whence == SEEK_SET) + size = FFMIN(sizeof(tmp), pos - c->logical_pos); + ret = cache_read(h, tmp, size); + if (ret == 0 && whence == SEEK_END) { + av_assert0(c->is_true_eof); + goto resolve_eof; + } + if (ret < 0) { + return ret; + } + } + return c->logical_pos; + } + } if (ret >= 0) { c->logical_pos = ret; @@ -246,10 +271,24 @@ static int cache_close(URLContext *h) ffurl_close(c->inner); av_tree_destroy(c->root); - return 0; } +#define OFFSET(x) offsetof(Context, x) +#define D AV_OPT_FLAG_DECODING_PARAM + +static const AVOption options[] = { + { "read_ahead_limit", "Amount in bytes that may be read ahead when seeking isnt supported, -1 for unlimited", OFFSET(read_ahead_limit), AV_OPT_TYPE_INT, { .i64 = 65536 }, -1, INT_MAX, D }, + {NULL}, +}; + +static const AVClass cache_context_class = { + .class_name = "Cache", + .item_name = av_default_item_name, + .option = options, + .version = LIBAVUTIL_VERSION_INT, +}; + URLProtocol ff_cache_protocol = { .name = "cache", .url_open = cache_open, @@ -257,4 +296,5 @@ URLProtocol ff_cache_protocol = { .url_seek = cache_seek, .url_close = cache_close, .priv_data_size = sizeof(Context), + .priv_data_class = &cache_context_class, }; |