@@ -219,7 +219,6 @@ static int dss_sp_read_packet(AVFormatContext *s, AVPacket *pkt)
} else
read_size = DSS_FRAME_SIZE;
- ctx->counter -= read_size;
ctx->packet_size = DSS_FRAME_SIZE - 1;
ret = av_new_packet(pkt, DSS_FRAME_SIZE);
@@ -231,17 +230,16 @@ static int dss_sp_read_packet(AVFormatContext *s, AVPacket *pkt)
pkt->stream_index = 0;
s->bit_rate = 8LL * ctx->packet_size * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
- if (ctx->counter < 0) {
- int size2 = ctx->counter + read_size;
-
- ret = avio_read(s->pb, ctx->dss_sp_buf + offset + buff_offset,
- size2 - offset);
- if (ret < size2 - offset)
+ if (ctx->counter < read_size) {
+ ret = avio_read(s->pb, ctx->dss_sp_buf + buff_offset,
+ ctx->counter);
+ if (ret < ctx->counter)
goto error_eof;
+ offset = ctx->counter;
dss_skip_audio_header(s, pkt);
- offset = size2;
}
+ ctx->counter -= read_size;
ret = avio_read(s->pb, ctx->dss_sp_buf + offset + buff_offset,
read_size - offset);
@@ -278,7 +276,7 @@ static int dss_723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
size = frame_size[byte & 3];
ctx->packet_size = size;
- ctx->counter -= size;
+ ctx->counter--;
ret = av_new_packet(pkt, size);
if (ret < 0)
@@ -288,27 +286,26 @@ static int dss_723_1_read_packet(AVFormatContext *s, AVPacket *pkt)
pkt->data[0] = byte;
offset = 1;
pkt->duration = 240;
- s->bit_rate = 8LL * size * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
+ s->bit_rate = 8LL * size-- * st->codecpar->sample_rate * 512 / (506 * pkt->duration);
pkt->stream_index = 0;
- if (ctx->counter < 0) {
- int size2 = ctx->counter + size;
-
+ if (ctx->counter < size) {
ret = avio_read(s->pb, pkt->data + offset,
- size2 - offset);
- if (ret < size2 - offset) {
+ ctx->counter);
+ if (ret < ctx->counter)
return ret < 0 ? ret : AVERROR_EOF;
- }
+ offset += ctx->counter;
+ size -= ctx->counter;
+ ctx->counter = 0;
dss_skip_audio_header(s, pkt);
- offset = size2;
}
+ ctx->counter -= size;
- ret = avio_read(s->pb, pkt->data + offset, size - offset);
- if (ret < size - offset) {
+ ret = avio_read(s->pb, pkt->data + offset, size);
+ if (ret < size)
return ret < 0 ? ret : AVERROR_EOF;
- }
return pkt->size;
}
The DSS demuxer currently decrements a counter that should be positive at the beginning of read_packet; should it become negative, it means that the data to be read can't be read contiguosly, but has to be read in two parts. In this case the counter is incremented again after the first read if said read succeeded; if not, the counter stays negative. This can lead to problems in further read_packet calls; in tickets #9020 and #9023 it led to segfaults if one tries to seek lateron if the seek failed and generic seek tried to read from the beginning. But it could also happen when av_new_packet() failed and the user attempted to read again afterwards. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com> --- libavformat/dss.c | 37 +++++++++++++++++-------------------- 1 file changed, 17 insertions(+), 20 deletions(-)