From 6d354aeb29d257ae64ad6a055d210dd6b191d5bc Mon Sep 17 00:00:00 2001 From: Andreas Rheinhardt Date: Tue, 8 Oct 2019 07:41:14 +0200 Subject: [PATCH] avformat/mpeg: Remove secondary packet for reading VobSub When vobsub_read_packet() reads a packet, it uses a dedicated AVPacket to get the subtitle timing and position from an FFDemuxSubtitlesQueue (which has been filled with this data during reading the idx file in vobsub_read_header); afterwards the actual subtitle data is read into the packet destined for output and the timing and position are copied to this packet. Afterwards, the local packet is unreferenced. This can be simplified: Simply use the output packet to get the timing and position from the FFDemuxSubtitlesQueue. The packet's size will be zero afterwards, so that it can be directly used to read the actual subtitle data. This makes copying the packet fields as well as unreferencing the local packet unecessary and also removes an instance of usage of sizeof(AVPacket) in libavformat. The only difference is that the returned packet will already be flagged as a keyframe. This currently only happens in compute_pkt_fields(). Signed-off-by: Andreas Rheinhardt Signed-off-by: Michael Niedermayer --- libavformat/mpeg.c | 23 +++++++---------------- 1 file changed, 7 insertions(+), 16 deletions(-) diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c index e61851bba5..fad7c7fd55 100644 --- a/libavformat/mpeg.c +++ b/libavformat/mpeg.c @@ -920,7 +920,6 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt) FFDemuxSubtitlesQueue *q; AVIOContext *pb = vobsub->sub_ctx->pb; int ret, psize, total_read = 0, i; - AVPacket idx_pkt = { 0 }; int64_t min_ts = INT64_MAX; int sid = 0; @@ -935,24 +934,22 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt) } } q = &vobsub->q[sid]; - ret = ff_subtitles_queue_read_packet(q, &idx_pkt); + /* The returned packet will have size zero, + * so that it can be directly used with av_grow_packet. */ + ret = ff_subtitles_queue_read_packet(q, pkt); if (ret < 0) return ret; /* compute maximum packet size using the next packet position. This is * useful when the len in the header is non-sense */ if (q->current_sub_idx < q->nb_subs) { - psize = q->subs[q->current_sub_idx].pos - idx_pkt.pos; + psize = q->subs[q->current_sub_idx].pos - pkt->pos; } else { int64_t fsize = avio_size(pb); - psize = fsize < 0 ? 0xffff : fsize - idx_pkt.pos; + psize = fsize < 0 ? 0xffff : fsize - pkt->pos; } - avio_seek(pb, idx_pkt.pos, SEEK_SET); - - av_init_packet(pkt); - pkt->size = 0; - pkt->data = NULL; + avio_seek(pb, pkt->pos, SEEK_SET); do { int n, to_read, startcode; @@ -976,7 +973,7 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt) total_read += pkt_size; /* the current chunk doesn't match the stream index (unlikely) */ - if ((startcode & 0x1f) != s->streams[idx_pkt.stream_index]->id) + if ((startcode & 0x1f) != s->streams[pkt->stream_index]->id) break; ret = av_grow_packet(pkt, to_read); @@ -988,16 +985,10 @@ static int vobsub_read_packet(AVFormatContext *s, AVPacket *pkt) pkt->size -= to_read - n; } while (total_read < psize); - pkt->pts = pkt->dts = idx_pkt.pts; - pkt->pos = idx_pkt.pos; - pkt->stream_index = idx_pkt.stream_index; - - av_packet_unref(&idx_pkt); return 0; fail: av_packet_unref(pkt); - av_packet_unref(&idx_pkt); return ret; }