HLS support

This change adds the (tiny) changes required to the HLS demuxer for it
to support jsfetch as a backend, and thus to support HLS on platforms
that provide W3C fetch.

configs/all/ffmpeg-config.txt

@@ -93,6 +93,8 @@
 --enable-decoder=qtrle
 --enable-encoder=qtrle
 --enable-protocol=jsfetch
+--enable-demuxer=hls
+--enable-muxer=hls
 --enable-libopenh264
 --enable-decoder=libopenh264
 --enable-encoder=libopenh264

configs/mkconfigs.js

@@ -41,6 +41,7 @@ const configs = [
     ["prores", ["format-mp4", "format-webm", "swscale", "codec-prores"]],
     ["qtrle", ["format-mov", "swscale", "codec-qtrle"]],
     ["jsfetch", ["protocol-jsfetch"]],
+    ["hls", ["format-hls"]],
 
     // Patent and/or license encumbered encoders
     ["mediarecorder-openh264", ["format-ogg", "format-webm", "codec-libopus", "format-mp4", "codec-aac", "format-flac", "codec-flac", "swscale", "libvpx", "codec-libvpx_vp8", "decoder-h264", "codec-libopenh264"]],

docs/API.md

@@ -33,8 +33,8 @@ Initializes a muxer all at once, opening the file and initializing the format
 context. You can provide the format as a libav numerical code (`oformat`) or as
 a name (`format_name`), the filename to write to (which can of course be a
 device) (`filename`), and/or create it as a writer device automatically
-(`device`). You have the option not to open the file (`open=false`), in which
-case you will need to provide your own `pb`.
+(`device`). You have the option not to open the file (`open=false`, the
+default), in which case you will need to provide your own `pb`.
 
 For the streams to mux, each stream is in the form `[number, number, number]`,
 consisting of the codec context, `time_base_num`, and `time_base_den`,

docs/IO.md

@@ -10,7 +10,8 @@ JavaScript's `fetch` function to stream data over HTTP or HTTPS. This is not
 currently enabled by default in any build (other than "all"), but using an
 experimental build with `jsfetch` enabled, simply use, e.g., the URL
 `jsfetch:https://example.com/video.mkv` to use fetch. `jsfetch` does not
-currently support seeking or writing, only reading in a stream.
+currently support seeking or writing, only reading in a stream. If you enable
+the HLS demuxer, `jsfetch` supports reading from HLS streams as well.
 
 
 ## Reading

mk/ffmpeg.mk

@@ -114,8 +114,9 @@ build/ffmpeg-$(FFMPEG_VERSION)/PATCHED: build/ffmpeg-$(FFMPEG_VERSION)/configure
 	cd build/ffmpeg-$(FFMPEG_VERSION) ; ( test -e PATCHED || patch -p1 -i ../../patches/ffmpeg.diff )
 	touch $@
 
-build/ffmpeg-$(FFMPEG_VERSION)/libavformat/jsfetch.c: build/ffmpeg-$(FFMPEG_VERSION)/configure
-	cp patches/jsfetch.c $@
+build/ffmpeg-$(FFMPEG_VERSION)/libavformat/jsfetch.c: patches/jsfetch.c \
+	build/ffmpeg-$(FFMPEG_VERSION)/configure
+	cp $< $@
 	touch $@
 
 build/ffmpeg-$(FFMPEG_VERSION)/configure: build/ffmpeg-$(FFMPEG_VERSION).tar.xz

mk/ffmpeg.mk.m4

@@ -60,8 +60,9 @@ build/ffmpeg-$(FFMPEG_VERSION)/PATCHED: build/ffmpeg-$(FFMPEG_VERSION)/configure
 	cd build/ffmpeg-$(FFMPEG_VERSION) ; ( test -e PATCHED || patch -p1 -i ../../patches/ffmpeg.diff )
 	touch $@
 
-build/ffmpeg-$(FFMPEG_VERSION)/libavformat/jsfetch.c: build/ffmpeg-$(FFMPEG_VERSION)/configure
-	cp patches/jsfetch.c $@
+build/ffmpeg-$(FFMPEG_VERSION)/libavformat/jsfetch.c: patches/jsfetch.c \
+	build/ffmpeg-$(FFMPEG_VERSION)/configure
+	cp $< $@
 	touch $@
 
 build/ffmpeg-$(FFMPEG_VERSION)/configure: build/ffmpeg-$(FFMPEG_VERSION).tar.xz

patches/ffmpeg.diff

@@ -11962,6 +11962,19 @@ index cbdf48d..aeb3767 100644
      if (ret == 0 && c->follow)
          return AVERROR(EAGAIN);
      if (ret == 0)
+diff --git a/libavformat/hls.c b/libavformat/hls.c
+index 8a96a37..ede65d6 100644
+--- a/libavformat/hls.c
++++ b/libavformat/hls.c
+@@ -673,6 +673,8 @@ static int open_url(AVFormatContext *s, AVIOContext **pb, const char *url,
+         is_http = 1;
+     } else if (av_strstart(proto_name, "data", NULL)) {
+         ;
++    } else if (av_strstart(proto_name, "jsfetch", NULL)) {
++        ;
+     } else
+         return AVERROR_INVALIDDATA;
+
 diff --git a/libavformat/oggdec.c b/libavformat/oggdec.c
 index 3b19e0b..474d82d 100644
 --- a/libavformat/oggdec.c

patches/jsfetch.c

@@ -99,8 +99,8 @@ static int jsfetch_open(URLContext *h, const char *url, int flags, AVDictionary
  * Read from a fetch connection (JavaScript side).
  */
 EM_JS(int, jsfetch_read_js, (int idx, unsigned char *toBuf, int size), {
+    var jsfo = Module.libavjsJSFetch.fetches[idx];
     return Asyncify.handleAsync(function() { return Promise.all([]).then(function() {
-        var jsfo = Module.libavjsJSFetch.fetches[idx];
         if (jsfo.buf || jsfo.rej) {
             // Already have data
             var fromBuf = jsfo.buf;
@@ -109,7 +109,7 @@ EM_JS(int, jsfetch_read_js, (int idx, unsigned char *toBuf, int size), {
             if (fromBuf) {
                 if (fromBuf.done) {
                     // EOF
-                    return 0;
+                    return -0x20464f45 /* AVERROR_EOF */;
                 }
                 if (fromBuf.value.length > size) {
                     // Return some of the buffer
@@ -138,9 +138,10 @@ EM_JS(int, jsfetch_read_js, (int idx, unsigned char *toBuf, int size), {
         }
 
         // The next data isn't available yet. Force them to wait.
-        return new Promise(function(res) {
-            setTimeout(function() { res(-6 /* EAGAIN */); }, 100);
-        });
+        return Promise.race([
+            jsfo.next,
+            new Promise(function(res) { setTimeout(res, 100); })
+        ]).then(function() { return -6 /* EAGAIN */; });
     }); });
 });
 
@@ -182,6 +183,6 @@ const URLProtocol ff_jsfetch_protocol = {
     .priv_data_size     = sizeof(JSFetchContext),
     .priv_data_class    = &jsfetch_context_class,
     .flags              = URL_PROTOCOL_FLAG_NETWORK,
-    .default_whitelist  = "http,https"
+    .default_whitelist  = "jsfetch,http,https"
 };
 #endif