lavf: add write_uncoded_frame() API.

libavformat/avformat.h

@@ -512,6 +512,17 @@ typedef struct AVOutputFormat {
      */
     int (*control_message)(struct AVFormatContext *s, int type,
                            void *data, size_t data_size);
+
+    /**
+     * Write an uncoded AVFrame.
+     *
+     * See av_write_uncoded_frame() for details.
+     *
+     * The library will free *frame afterwards, but the muxer can prevent it
+     * by setting the pointer to NULL.
+     */
+    int (*write_uncoded_frame)(struct AVFormatContext *, int stream_index,
+                               AVFrame **frame, unsigned flags);
 } AVOutputFormat;
 /**
  * @}
@@ -2092,6 +2103,44 @@ int av_write_frame(AVFormatContext *s, AVPacket *pkt);
  */
 int av_interleaved_write_frame(AVFormatContext *s, AVPacket *pkt);
 
+/**
+ * Write a uncoded frame to an output media file.
+ *
+ * The frame must be correctly interleaved according to the container
+ * specification; if not, then av_interleaved_write_frame() must be used.
+ *
+ * See av_interleaved_write_frame() for details.
+ */
+int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
+                           AVFrame *frame);
+
+/**
+ * Write a uncoded frame to an output media file.
+ *
+ * If the muxer supports it, this function allows to write an AVFrame
+ * structure directly, without encoding it into a packet.
+ * It is mostly useful for devices and similar special muxers that use raw
+ * video or PCM data and will not serialize it into a byte stream.
+ *
+ * To test whether it is possible to use it with a given muxer and stream,
+ * use av_write_uncoded_frame_query().
+ *
+ * The caller gives up ownership of the frame and must not access it
+ * afterwards.
+ *
+ * @return  >=0 for success, a negative code on error
+ */
+int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
+                                       AVFrame *frame);
+
+/**
+ * Test whether a muxer supports uncoded frame.
+ *
+ * @return  >=0 if an uncoded frame can be written to that muxer and stream,
+ *          <0 if not
+ */
+int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index);
+
 /**
  * Write the stream trailer to an output media file and free the
  * file private data.

libavformat/internal.h

@@ -398,4 +398,18 @@ int ff_rfps_add_frame(AVFormatContext *ic, AVStream *st, int64_t dts);
 
 void ff_rfps_calculate(AVFormatContext *ic);
 
+/**
+ * Flags for AVFormatContext.write_uncoded_frame()
+ */
+enum AVWriteUncodedFrameFlags {
+
+    /**
+     * Query whether the feature is possible on this stream.
+     * The frame argument is ignored.
+     */
+    AV_WRITE_UNCODED_FRAME_QUERY           = 0x0001,
+
+};
+
+
 #endif /* AVFORMAT_INTERNAL_H */

libavformat/mux.c

@@ -417,6 +417,15 @@ int avformat_write_header(AVFormatContext *s, AVDictionary **options)
     return 0;
 }
 
+#define AV_PKT_FLAG_UNCODED_FRAME 0x2000
+
+/* Note: using sizeof(AVFrame) from outside lavu is unsafe in general, but
+   it is only being used internally to this file as a consistency check.
+   The value is chosen to be very unlikely to appear on its own and to cause
+   immediate failure if used anywhere as a real size. */
+#define UNCODED_FRAME_PACKET_SIZE (INT_MIN / 3 * 2 + (int)sizeof(AVFrame))
+
+
 //FIXME merge with compute_pkt_fields
 static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt)
 {
@@ -482,7 +491,9 @@ static int compute_pkt_fields2(AVFormatContext *s, AVStream *st, AVPacket *pkt)
     /* update pts */
     switch (st->codec->codec_type) {
     case AVMEDIA_TYPE_AUDIO:
-        frame_size = ff_get_audio_frame_size(st->codec, pkt->size, 1);
+        frame_size = (pkt->flags & AV_PKT_FLAG_UNCODED_FRAME) ?
+                     ((AVFrame *)pkt->data)->nb_samples :
+                     ff_get_audio_frame_size(st->codec, pkt->size, 1);
 
         /* HACK/FIXME, we skip the initial 0 size packets as they are most
          * likely equal to the encoder delay, but it would be better if we
@@ -549,7 +560,14 @@ static int write_packet(AVFormatContext *s, AVPacket *pkt)
     }
 
     did_split = av_packet_split_side_data(pkt);
+    if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
+        AVFrame *frame = (AVFrame *)pkt->data;
+        av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
+        ret = s->oformat->write_uncoded_frame(s, pkt->stream_index, &frame, 0);
+        av_frame_free(&frame);
+    } else {
         ret = s->oformat->write_packet(s, pkt);
+    }
 
     if (s->flush_packets && s->pb && ret >= 0 && s->flags & AVFMT_FLAG_FLUSH_PACKETS)
         avio_flush(s->pb);
@@ -632,8 +650,13 @@ FF_DISABLE_DEPRECATION_WARNINGS
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif
     pkt->buf       = NULL;
+    if ((pkt->flags & AV_PKT_FLAG_UNCODED_FRAME)) {
+        av_assert0(pkt->size == UNCODED_FRAME_PACKET_SIZE);
+        av_assert0(((AVFrame *)pkt->data)->buf);
+    } else {
         av_dup_packet(&this_pktl->pkt);  // duplicate the packet if it uses non-allocated memory
         av_copy_packet_side_data(&this_pktl->pkt, &this_pktl->pkt); // copy side data
+    }
 
     if (s->streams[pkt->stream_index]->last_in_packet_buffer) {
         next_point = &(st->last_in_packet_buffer->next);
@@ -932,3 +955,51 @@ int ff_write_chained(AVFormatContext *dst, int dst_stream, AVPacket *pkt,
                                           dst->streams[dst_stream]->time_base);
     return av_write_frame(dst, &local_pkt);
 }
+
+static int av_write_uncoded_frame_internal(AVFormatContext *s, int stream_index,
+                                           AVFrame *frame, int interleaved)
+{
+    AVPacket pkt, *pktp;
+
+    av_assert0(s->oformat);
+    if (!s->oformat->write_uncoded_frame)
+        return AVERROR(ENOSYS);
+
+    if (!frame) {
+        pktp = NULL;
+    } else {
+        pktp = &pkt;
+        av_init_packet(&pkt);
+        pkt.data = (void *)frame;
+        pkt.size         = UNCODED_FRAME_PACKET_SIZE;
+        pkt.pts          =
+        pkt.dts          = frame->pts;
+        pkt.duration     = av_frame_get_pkt_duration(frame);
+        pkt.stream_index = stream_index;
+        pkt.flags |= AV_PKT_FLAG_UNCODED_FRAME;
+    }
+
+    return interleaved ? av_interleaved_write_frame(s, pktp) :
+                         av_write_frame(s, pktp);
+}
+
+int av_write_uncoded_frame(AVFormatContext *s, int stream_index,
+                           AVFrame *frame)
+{
+    return av_write_uncoded_frame_internal(s, stream_index, frame, 0);
+}
+
+int av_interleaved_write_uncoded_frame(AVFormatContext *s, int stream_index,
+                                       AVFrame *frame)
+{
+    return av_write_uncoded_frame_internal(s, stream_index, frame, 1);
+}
+
+int av_write_uncoded_frame_query(AVFormatContext *s, int stream_index)
+{
+    av_assert0(s->oformat);
+    if (!s->oformat->write_uncoded_frame)
+        return AVERROR(ENOSYS);
+    return s->oformat->write_uncoded_frame(s, stream_index, NULL,
+                                           AV_WRITE_UNCODED_FRAME_QUERY);
+}