lavf: add field for how duration is estimated

Signed-off-by: Michael Bradshaw <mbradshaw@sorensonmedia.com>

1 files changed, 17 insertions, 0 deletions

diff --git a/libavformat/avformat.h b/libavformat/avformat.h
index 19441f8e21..8650b0836a 100644
--- a/libavformat/avformat.h
+++ b/libavformat/avformat.h
@@ -1099,8 +1099,25 @@ typedef struct AVFormatContext {
     int raw_packet_buffer_remaining_size;
 
     int avio_flags;
+
+    /**
+     * The duration field can be estimated through various ways, and this field can be used
+     * to know how the duration was estimated.
+     */
+    enum {
+        AVFMT_DURATION_FROM_PTS,    ///< duration accurately estimated from PTSes
+        AVFMT_DURATION_FROM_STREAM, ///< duration estimated from a stream with a known duration
+        AVFMT_DURATION_FROM_BITRATE ///< duration estimated from bitrate (less accurate)
+    } duration_estimation_method;
 } AVFormatContext;
 
+/**
+ * Returns the method used to set ctx->duration.
+ *
+ * @return AVFMT_DURATION_FROM_PTS, AVFMT_DURATION_FROM_STREAM, or AVFMT_DURATION_FROM_BITRATE.
+ */
+int av_fmt_ctx_get_duration_estimation_method(const AVFormatContext* ctx);
+
 typedef struct AVPacketList {
     AVPacket pkt;
     struct AVPacketList *next;