Support decoding only a selection of the encoded XMA streams.
Previously, the decoder assumed it was decoding all available streams.
---
libavcodec/wmaprodec.c | 65 ++++++++++++++++++++++++------------------
1 file changed, 38 insertions(+), 27 deletions(-)
diff --git a/libavcodec/wmaprodec.c b/libavcodec/wmaprodec.c
index 66271c4037..b957b1d1ea 100644
--- a/libavcodec/wmaprodec.c
+++ b/libavcodec/wmaprodec.c
@@ -1814,7 +1814,44 @@ static int xma_decode_packet(AVCodecContext *avctx, void
*data,
XMADecodeCtx *s = avctx->priv_data;
int got_stream_frame_ptr = 0;
AVFrame *frame = data;
- int i, ret, offset = INT_MAX;
+ int i, ret, skip_current_packet;
+ int offset = INT_MAX;
+
+ /* find the owner stream of the new XMA packet that belongs to on of our
streams
+ * XMA streams find their packets following packet_skips
+ * there may be other packets in between if we are not responsible for all
streams
+ * (at start there is one packet per stream, then interleave
non-linearly). */
+ if (s->xma[s->current_stream].packet_done ||
+ s->xma[s->current_stream].packet_loss) {
+ /* select stream with lowest skip_packets (= uses next packet) */
+ if (s->xma[s->current_stream].skip_packets != 0) {
+ int min[2];
+
+ min[0] = s->xma[0].skip_packets;
+ min[1] = i = 0;
+
+ for (i = 1; i < s->num_streams; i++) {
+ if (s->xma[i].skip_packets < min[0]) {
+ min[0] = s->xma[i].skip_packets;
+ min[1] = i;
+ }
+ }
+
+ s->current_stream = min[1];
+ }
+
+ skip_current_packet = !!s->xma[s->current_stream].skip_packets;
+
+ /* advance all stream packet skip counts */
+ for (i = 0; i < s->num_streams; i++) {
+ s->xma[i].skip_packets = FFMAX(0, s->xma[i].skip_packets - 1);
+ }
+
+ /* if we are not responsible for every stream, make sure we ignore
+ * XMA packets not belonging to one of our streams */
+ if (skip_current_packet)
+ return avctx->block_align;
+ }
if (!s->frames[s->current_stream]->data[0]) {
s->frames[s->current_stream]->nb_samples = 512;
@@ -1846,34 +1883,8 @@ static int xma_decode_packet(AVCodecContext *avctx, void
*data,
return ret;
}
- /* find next XMA packet's owner stream, and update.
- * XMA streams find their packets following packet_skips
- * (at start there is one packet per stream, then interleave
non-linearly). */
if (s->xma[s->current_stream].packet_done ||
s->xma[s->current_stream].packet_loss) {
-
- /* select stream with 0 skip_packets (= uses next packet) */
- if (s->xma[s->current_stream].skip_packets != 0) {
- int min[2];
-
- min[0] = s->xma[0].skip_packets;
- min[1] = i = 0;
-
- for (i = 1; i < s->num_streams; i++) {
- if (s->xma[i].skip_packets < min[0]) {
- min[0] = s->xma[i].skip_packets;
- min[1] = i;
- }
- }
-
- s->current_stream = min[1];
- }
-
- /* all other streams skip next packet */
- for (i = 0; i < s->num_streams; i++) {
- s->xma[i].skip_packets = FFMAX(0, s->xma[i].skip_packets - 1);
- }
-
/* copy samples from buffer to output if possible */
for (i = 0; i < s->num_streams; i++) {
offset = FFMIN(offset, s->offset[i]);
--
2.30.2
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