[FFmpeg-devel] [PATCH] avformat/http: Add short_seek_size option

[Derek Buitenhuis]

In 45bfe8b838275235412777dd430206d9a24eb3ee, short_seek_threshold was removed
from the public AVIO struct. Although this option was private and not intended
to be used by public API users, it was nonetheless, because it provided functionality
that could otherwise not be gained via public API.

This was especially important for networked I/O like HTTP, where the internal
size for lavf could be way to small depending on the specifics of a user's
usecase, such as reading interlavd media files from cloud storage.

Add an AVOption to make this functionality accessible to the HTTP client.

Signed-off-by: Derek Buitenhuis <derek.buitenhuis at gmail.com>
---
Same as last version but I'm marking it as non-RFC. I think I prefer the AVOption approach.

Comments welcome.
---
 libavformat/http.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavformat/http.c b/libavformat/http.c
index 476b9a8456..0dc1ce0f43 100644
--- a/libavformat/http.c
+++ b/libavformat/http.c
@@ -126,6 +126,7 @@ typedef struct HTTPContext {
     int is_multi_client;
     HandshakeState handshake_step;
     int is_connected_server;
+    int short_seek_size;
 } HTTPContext;
 
 #define OFFSET(x) offsetof(HTTPContext, x)
@@ -167,6 +168,7 @@ static const AVOption options[] = {
     { "listen", "listen on HTTP", OFFSET(listen), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, D | E },
     { "resource", "The resource requested by a client", OFFSET(resource), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "reply_code", "The http status code to return to a client", OFFSET(reply_code), AV_OPT_TYPE_INT, { .i64 = 200}, INT_MIN, 599, E},
+    { "short_seek_size", "Threshold to favor readahead over seek.", OFFSET(short_seek_size), AV_OPT_TYPE_INT, { .i64 = -1 }, 1, INT64_MAX, D },
     { NULL }
 };
 
@@ -1842,6 +1844,8 @@ static int http_get_file_handle(URLContext *h)
 static int http_get_short_seek(URLContext *h)
 {
     HTTPContext *s = h->priv_data;
+    if (s->short_seek_size >= 1)
+        return s->short_seek_size;
     return ffurl_get_short_seek(s->hd);
 }
 
-- 
2.32.0