1 files changed, 32 insertions, 43 deletions

diff --git a/demux/packet.c b/demux/packet.c
index 77ea78f7cc..2008113600 100644
--- a/demux/packet.c
+++ b/demux/packet.c
@@ -29,55 +29,58 @@
 static void packet_destroy(void *ptr)
 {
     struct demux_packet *dp = ptr;
-    talloc_free(dp->avpacket);
-    av_free(dp->allocation);
+    av_packet_unref(dp->avpacket);
 }
 
-static struct demux_packet *create_packet(size_t len)
+// This actually preserves only data and side data, not PTS/DTS/pos/etc.
+// It also allows avpkt->data==NULL with avpkt->size!=0 - the libavcodec API
+// does not allow it, but we do it to simplify new_demux_packet().
+struct demux_packet *new_demux_packet_from_avpacket(struct AVPacket *avpkt)
 {
-    if (len > 1000000000) {
+    if (avpkt->size > 1000000000) {
         fprintf(stderr, "Attempt to allocate demux packet over 1 GB!\n");
         abort();
     }
     struct demux_packet *dp = talloc(NULL, struct demux_packet);
     talloc_set_destructor(dp, packet_destroy);
     *dp = (struct demux_packet) {
-        .len = len,
         .pts = MP_NOPTS_VALUE,
         .dts = MP_NOPTS_VALUE,
         .duration = -1,
         .pos = -1,
         .stream = -1,
+        .avpacket = talloc_zero(dp, AVPacket),
     };
-    return dp;
-}
-
-struct demux_packet *new_demux_packet(size_t len)
-{
-    struct demux_packet *dp = create_packet(len);
-    dp->buffer = av_malloc(len + FF_INPUT_BUFFER_PADDING_SIZE);
-    if (!dp->buffer) {
-        fprintf(stderr, "Memory allocation failure!\n");
+    av_init_packet(dp->avpacket);
+    int r = -1;
+    if (avpkt->data) {
+        // We hope that this function won't need/access AVPacket input padding,
+        // because otherwise new_demux_packet_from() wouldn't work.
+        r = av_packet_ref(dp->avpacket, avpkt);
+    } else {
+        r = av_new_packet(dp->avpacket, avpkt->size);
+    }
+    if (r < 0) {
+        fprintf(stderr, "Out of memory when referencing packet.\n");
         abort();
     }
-    memset(dp->buffer + len, 0, FF_INPUT_BUFFER_PADDING_SIZE);
-    dp->allocation = dp->buffer;
+    dp->buffer = dp->avpacket->data;
+    dp->len = dp->avpacket->size;
     return dp;
 }
 
-// data must already have suitable padding, and does not copy the data
-struct demux_packet *new_demux_packet_fromdata(void *data, size_t len)
+// Input data doesn't need to be padded.
+struct demux_packet *new_demux_packet_from(void *data, size_t len)
 {
-    struct demux_packet *dp = create_packet(len);
-    dp->buffer = data;
-    return dp;
+    AVPacket pkt = { .data = data, .size = len };
+    return new_demux_packet_from_avpacket(&pkt);
 }
 
-struct demux_packet *new_demux_packet_from(void *data, size_t len)
+struct demux_packet *new_demux_packet(size_t len)
 {
-    struct demux_packet *dp = new_demux_packet(len);
-    memcpy(dp->buffer, data, len);
-    return dp;
+    assert(len <= INT_MAX);
+    AVPacket pkt = { .data = NULL, .size = len };
+    return new_demux_packet_from_avpacket(&pkt);
 }
 
 void demux_packet_shorten(struct demux_packet *dp, size_t len)
@@ -92,28 +95,14 @@ void free_demux_packet(struct demux_packet *dp)
     talloc_free(dp);
 }
 
-static void destroy_avpacket(void *pkt)
-{
-    av_free_packet(pkt);
-}
-
 struct demux_packet *demux_copy_packet(struct demux_packet *dp)
 {
     struct demux_packet *new = NULL;
     if (dp->avpacket) {
-        assert(dp->buffer == dp->avpacket->data);
-        assert(dp->len == dp->avpacket->size);
-        AVPacket *newavp = talloc_zero(NULL, AVPacket);
-        talloc_set_destructor(newavp, destroy_avpacket);
-        av_init_packet(newavp);
-        if (av_packet_ref(newavp, dp->avpacket) < 0)
-            abort();
-        new = new_demux_packet_fromdata(newavp->data, newavp->size);
-        new->avpacket = newavp;
-    }
-    if (!new) {
-        new = new_demux_packet(dp->len);
-        memcpy(new->buffer, dp->buffer, new->len);
+        new = new_demux_packet_from_avpacket(dp->avpacket);
+    } else {
+        // Some packets might be not created by new_demux_packet*().
+        new = new_demux_packet_from(dp->buffer, dp->len);
     }
     new->pts = dp->pts;
     new->dts = dp->dts;