Clean up Content-Range handling for playback

Transcoding can't cleanly support Content-Range, so ignore it if we
receive it and send 'Accept-Ranges: none' so smart clients won't send
it.

The logic that determines when enough has been streamed that the
stream should be recorded in the stats was complexified. Since we've
given up on predetermining the file size for transcodes we have to
account for that. Content-Ranges that start well into the file now
won't update the stats, since we've probably already done it (this
assumption is wrong if the client immediately seeks, but nothing's
perfect.)  Finally, a straight file size / 4 seemed too straighforward,
so small files will be / 1.1 and large files will have the value capped.

1 files changed, 56 insertions, 26 deletions

diff --git a/play/index.php b/play/index.php
index fb50a6ce..86932f81 100644
--- a/play/index.php
+++ b/play/index.php
@@ -57,9 +57,6 @@ if ($type == 'playlist') {
 $demo_id	= scrub_in($_REQUEST['demo_id']);
 $random		= scrub_in($_REQUEST['random']);
 
-// Parse byte range request
-$n = sscanf($_SERVER['HTTP_RANGE'], "bytes=%d-%d",$start,$end);
-
 /* First things first, if we don't have a uid/oid stop here */
 if (empty($oid) && empty($demo_id) && empty($random)) {
 	debug_event('play', 'No object UID specified, nothing to play', 2);
@@ -226,7 +223,7 @@ if ($catalog->catalog_type == 'remote') {
 	$sid   = xmlRpcClient::ampache_create_stream_session($match['1'],$token);
 
 	$extra_info = "&xml_rpc=1&sid=$sid";
-	header("Location: " . $media->file . $extra_info);
+	header('Location: ' . $media->file . $extra_info);
 	debug_event('xmlrpc-stream',"Start XML-RPC Stream - " . $media->file . $extra_info,'5');
 
 	/* If this is a voting tmp playlist remove the entry, we do this regardless of play amount */
@@ -304,8 +301,6 @@ if ($_GET['action'] == 'download' AND Config::get('download')) {
 
 } // if they are trying to download and they can
 
-header("Accept-Ranges: bytes" );
-
 // Prevent the script from timing out
 set_time_limit(0);
 
@@ -330,12 +325,14 @@ if (((Config::get('transcode') == 'always' && !$video) ||
 		'Decided to transcode. Transcode:' . Config::get('transcode') . 
 		' Native Stream: ' . ($media->native_stream() ? 'true' : 'false') .
 		' Remote: ' . ($downsample_remote ? 'true' : 'false'), 5);
+	header('Accept-Ranges: none');
 	$media->set_transcode();
 	$fp = Stream::start_transcode($media, $media_name, $start);
 	$media_name = $media->f_artist_full . " - " . $media->title . "." . $media->type;
 	$transcoded = true;
 } // end if downsampling
 else {
+	header('Accept-Ranges: bytes');
 	$fp = fopen($media->file, 'rb');
 	$transcoded = false; 
 }
@@ -350,59 +347,92 @@ if (get_class($media) == 'Song') {
 	Stream::insert_now_playing($media->id,$uid,$media->time,$sid,get_class($media));
 }
 
+if ($transcoded) {
+	$stream_size = null;
+}
+else {
+	$stream_size = $media->size;
+}
+
+// Handle Content-Range
+
+sscanf($_SERVER['HTTP_RANGE'], "bytes=%d-%d", $start, $end);
+
 if ($start > 0 || $end > 0 ) {
 	// Calculate stream size from byte range
-	if(isset($end)) {
-		$end = min($end,$media->size-1);
-		$stream_size = ($end-$start)+1;
+	if (isset($end)) {
+		$end = min($end, $media->size - 1);
+		$stream_size = ($end - $start) + 1;
 	}
 	else {
 		$stream_size = $media->size - $start;
 	}
 
-	debug_event('play', 'Content-Range header received, skipping ' . $start . ' bytes out of ' . $media->size, 5);
-	$browser->downloadHeaders($media_name, $media->mime, false, $media->size);
-	if (!$transcoded) {
+	if ($transcoded) {
+		debug_event('play', 'Bad client behaviour. Content-Range header received, which we cannot fulfill due to transcoding', 1);
+		$stream_size = null;
+	}
+	else {
+		debug_event('play', 'Content-Range header received, skipping ' . $start . ' bytes out of ' . $media->size, 5);
 		fseek($fp, $start);
+
+		$range = $start . '-' . $end . '/' . $media->size;
+		header('HTTP/1.1 206 Partial Content');
+		header('Content-Range: bytes ' . $range);
 	}
-	$range = $start ."-". $end . "/" . $media->size;
-	header('HTTP/1.1 206 Partial Content');
-	header("Content-Range: bytes $range");
-	header("Content-Length: $stream_size");
 }
 else {
 	debug_event('play','Starting stream of ' . $media->file . ' with size ' . $media->size, 5);
-	header("Content-Length: $media->size");
-	$browser->downloadHeaders($media_name, $media->mime, false, $media->size);
-	$stream_size = $media->size;
 }
 
+$browser->downloadHeaders($media_name, $media->mime, false, $stream_size);
+
 $bytes_streamed = 0;
 
 // Actually do the streaming
 do {
-	$buf = fread($fp, min(2048, $stream_size - $bytes_streamed));
+	$read_size = $transcoded 
+		? 2048
+		: min(2048, $stream_size - $bytes_streamed);
+	$buf = fread($fp, $read_size);
 	print($buf);
 	$bytes_streamed += strlen($buf);
-} while (!feof($fp) && (connection_status() == 0) && ($bytes_streamed < $stream_size));
+} while (!feof($fp) && (connection_status() == 0) && ($transcoded || $bytes_streamed < $stream_size));
 
+$real_bytes_streamed = $bytes_streamed;
 // Need to make sure enough bytes were sent.
 if($bytes_streamed < $stream_size && (connection_status() == 0)) {
 	print(str_repeat(' ', $stream_size - $bytes_streamed));
+	$bytes_streamed = $stream_size;
 }
 
 // Make sure that a good chunk of the song has been played
-if ($bytes_streamed > $media->size / 2) {
-	// This check looks suspicious
+$target = 131072;
+if ($stream_size) {
+	if ($stream_size > 1048576) {
+		$target = 262144;
+	}
+	else if ($stream_size < 360448) {
+		$target = $stream_size / 1.1;
+	}
+	else {
+		$target = $stream_size / 4;
+	}
+}
+
+if ($start > $target) {
+	debug_event('play', 'Content-Range was more than ' . $target . ' into the file, not collecting stats', 5);
+}
+else if ($bytes_streamed > $target) {
+	// FIXME: This check looks suspicious
 	if (get_class($media) == 'Song') {
 		debug_event('play', 'Registering stats for ' . $media->title, 5);
 		$GLOBALS['user']->update_stats($media->id);
 		$media->set_played();
 	}
-
 }
 else {
-	debug_event('play', $bytes_streamed .' of ' . $media->size . ' streamed; not collecting stats', 5);
+	debug_event('play', $bytes_streamed .' of ' . $stream_size . ' streamed; not collecting stats', 5);
 }
 
 // If this is a democratic playlist remove the entry.
@@ -416,6 +446,6 @@ else {
 	fclose($fp);
 }
 
-debug_event('play', 'Stream ended at ' . $bytes_streamed . ' bytes out of ' . $media->size, 5);
+debug_event('play', 'Stream ended at ' . $bytes_streamed . ' (' . $real_bytes_streamed . ') bytes out of ' . $stream_size, 5);
 
 ?>