[FFmpeg-devel] [PATCH v4 4/9] avformat/utils: Don't initialize in loops

Andreas Rheinhardt andreas.rheinhardt at gmail.com
Fri Sep 20 23:39:11 EEST 2019


Since the recent changes to ff_packet_list_put, the source packet will
be automatically reset when the reference is moved to the packet list,
so that it is unnecessary to reinitialize the packet in the loops in
parse_packet and ff_read_packet; initializing once at the beginning is
enough.

This also fixes a potential, but currently unexisting problem: If the
raw packet buffer was initially not empty and probe_codec() failed,
then the packet returned would not be initialized. But given that
probe_codec() currently can't fail (always returns 0) this was not an
acute danger.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavformat/utils.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/libavformat/utils.c b/libavformat/utils.c
index 58e0db61da..cf326ad014 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -830,6 +830,10 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
     int ret, i, err;
     AVStream *st;
 
+    pkt->data = NULL;
+    pkt->size = 0;
+    av_init_packet(pkt);
+
     for (;;) {
         AVPacketList *pktl = s->internal->raw_packet_buffer;
         const AVPacket *pkt1;
@@ -847,9 +851,6 @@ int ff_read_packet(AVFormatContext *s, AVPacket *pkt)
             }
         }
 
-        pkt->data = NULL;
-        pkt->size = 0;
-        av_init_packet(pkt);
         ret = s->iformat->read_packet(s, pkt);
         if (ret < 0) {
             av_packet_unref(pkt);
@@ -1448,6 +1449,8 @@ static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
     int size      = pkt ? pkt->size : 0;
     int ret = 0, got_output = 0;
 
+    av_init_packet(&out_pkt);
+
     if (!pkt) {
         av_init_packet(&flush_pkt);
         pkt        = &flush_pkt;
@@ -1462,7 +1465,6 @@ static int parse_packet(AVFormatContext *s, AVPacket *pkt, int stream_index)
         int64_t next_pts = pkt->pts;
         int64_t next_dts = pkt->dts;
 
-        av_init_packet(&out_pkt);
         len = av_parser_parse2(st->parser, st->internal->avctx,
                                &out_pkt.data, &out_pkt.size, data, size,
                                pkt->pts, pkt->dts, pkt->pos);
-- 
2.20.1



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