Should this be handled generically in avcodec_decode_audio4 like
this, or only within the decode function for those codecs that
are ready to handle a change. The latter variant avoids issues
if there are codecs that screw up if e.g. sample_rate/channels
are changed on the fly, but means a call to the parameter change
function has to be added to all functions. Currently, this is
tested to work fine with nellymoser.
A third approach would be to add a codec flag for this, and only
apply the side data packet for those codecs.
---
libavcodec/utils.c | 40 ++++++++++++++++++++++++++++++++++++++++
1 files changed, 40 insertions(+), 0 deletions(-)
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 68fc525..841c5b3 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -40,6 +40,7 @@
#include "thread.h"
#include "audioconvert.h"
#include "internal.h"
+#include "bytestream.h"
#include <stdlib.h>
#include <stdarg.h>
#include <limits.h>
@@ -924,6 +925,43 @@ int attribute_align_arg
avcodec_decode_audio3(AVCodecContext *avctx, int16_t *sa
}
#endif
+static void apply_param_change(AVCodecContext *avctx, AVPacket *avpkt)
+{
+ int size = 0;
+ const uint8_t *data = av_packet_get_side_data(avpkt,
+ AV_PKT_DATA_PARAM_CHANGE, &size);
+ uint32_t flags;
+ if (!data || size < 4)
+ return;
+ flags = bytestream_get_le32(&data);
+ size -= 4;
+ if (size < 4) /* Required for any of the changes */
+ return;
+ if (flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_COUNT) {
+ avctx->channels = bytestream_get_le32(&data);
+ size -= 4;
+ }
+ if (flags & AV_SIDE_DATA_PARAM_CHANGE_CHANNEL_LAYOUT) {
+ if (size < 8)
+ return;
+ avctx->channel_layout = bytestream_get_le64(&data);
+ size -= 8;
+ }
+ if (size < 4)
+ return;
+ if (flags & AV_SIDE_DATA_PARAM_CHANGE_SAMPLE_RATE) {
+ avctx->sample_rate = bytestream_get_le32(&data);
+ size -= 4;
+ }
+ if (flags & AV_SIDE_DATA_PARAM_CHANGE_DIMENSIONS) {
+ if (size < 8)
+ return;
+ avctx->width = bytestream_get_le32(&data);
+ avctx->height = bytestream_get_le32(&data);
+ size -= 8;
+ }
+}
+
int attribute_align_arg avcodec_decode_audio4(AVCodecContext *avctx,
AVFrame *frame,
int *got_frame_ptr,
@@ -940,6 +978,8 @@ int attribute_align_arg
avcodec_decode_audio4(AVCodecContext *avctx,
return AVERROR(EINVAL);
}
+ apply_param_change(avctx, avpkt);
+
if ((avctx->codec->capabilities & CODEC_CAP_DELAY) || avpkt->size) {
ret = avctx->codec->decode(avctx, frame, got_frame_ptr, avpkt);
if (ret >= 0 && *got_frame_ptr) {
--
1.7.3.1
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