@@ -28,6 +28,10 @@

 typedef struct {

     int64_t data;

+    uint8_t *pkt_sizes;

+    int size_buffer_size;

+    int size_entries_used;

+    int packets;

 } CAFContext;

 static uint32_t codec_flags(enum CodecID codec_id) {

@@ -133,9 +137,9 @@ static int caf_write_header(AVFormatContext *s)

         return AVERROR_INVALIDDATA;

     }

-    if (!enc->block_align) {

-        av_log(s, AV_LOG_ERROR, "muxing with unknown or variable packet size not yet supported\n");

-        return AVERROR_PATCHWELCOME;

+    if (!enc->block_align && !pb->seekable) {

+        av_log(s, AV_LOG_ERROR, "Muxing variable packet size not supported on non seekable output\n");

+        return AVERROR_INVALIDDATA;

     }

     ffio_wfourcc(pb, "caff"); //< mFileType

@@ -169,13 +173,38 @@ static int caf_write_header(AVFormatContext *s)

 static int caf_write_packet(AVFormatContext *s, AVPacket *pkt)

 {

+    CAFContext *caf = s->priv_data;

+

     avio_write(s->pb, pkt->data, pkt->size);

+    if (!s->streams[0]->codec->block_align) {

+        void *pkt_sizes = caf->pkt_sizes;

+        int i, alloc_size = caf->size_entries_used + 5;

+        if (alloc_size < 0) {

+            caf->pkt_sizes = NULL;

+        } else {

+            caf->pkt_sizes = av_fast_realloc(caf->pkt_sizes,

+                                             &caf->size_buffer_size,

+                                             alloc_size);

+        }

+        if (!caf->pkt_sizes) {

+            av_free(pkt_sizes);

+            return AVERROR(ENOMEM);

+        }

+        for (i = 4; i > 0; i--) {

+            unsigned top = pkt->size >> i * 7;

+            if (top)

+                caf->pkt_sizes[caf->size_entries_used++] = 128 | top;

+        }

+        caf->pkt_sizes[caf->size_entries_used++] = pkt->size & 127;

+        caf->packets++;

+    }

     return 0;

 }

 static int caf_write_trailer(AVFormatContext *s)

 {

     AVIOContext *pb = s->pb;

+    AVCodecContext *enc = s->streams[0]->codec;

     if (pb->seekable) {

         CAFContext *caf = s->priv_data;

@@ -184,6 +213,17 @@ static int caf_write_trailer(AVFormatContext *s)

         avio_seek(pb, caf->data, SEEK_SET);

         avio_wb64(pb, file_size - caf->data - 8);

         avio_seek(pb, file_size, SEEK_SET);

+        if (!enc->block_align) {

+            ffio_wfourcc(pb, "pakt");

+            avio_wb64(pb, caf->size_entries_used + 24);

+            avio_wb64(pb, caf->packets); ///< mNumberPackets

+            avio_wb64(pb, caf->packets * samples_per_packet(enc->codec_id, enc->channels)); ///< mNumberValidFrames

+            avio_wb32(pb, 0); ///< mPrimingFrames

+            avio_wb32(pb, 0); ///< mRemainderFrames

+            avio_write(pb, caf->pkt_sizes, caf->size_entries_used);

+            av_freep(&caf->pkt_sizes);

+            caf->size_buffer_size = 0;

+        }

         avio_flush(pb);

     }

     return 0;