From: Hendrik Leppkes <h.leppkes@gmail.com>
Date: Wed, 29 Mar 2017 22:46:53 +0000 (+0200)
Subject: aacdec: track pce directly instead of overriding chan_config

aacdec: track pce directly instead of overriding chan_config

Modifying chan_config results in LATM decoding re-initializating every frame.
---

diff --git a/libavcodec/aacdec_template.c b/libavcodec/aacdec_template.c
index ec8b7c3b11..b3010698e3 100644
--- a/libavcodec/aacdec_template.c
+++ b/libavcodec/aacdec_template.c
@@ -557,7 +557,7 @@ static ChannelElement *get_che(AACContext *ac, int type, int elem_id)
 {
     /* For PCE based channel configurations map the channels solely based
      * on tags. */
-    if (!ac->oc[1].m4ac.chan_config) {
+    if (!ac->oc[1].m4ac.chan_config || ac->oc[1].m4ac.pce) {
         return ac->tag_che_map[type][elem_id];
     }
     // Allow single CPE stereo files to be signalled with mono configuration.
@@ -3040,7 +3040,7 @@ static int aac_decode_frame_int(AVCodecContext *avctx, void *data,
             } else {
                 err = output_configure(ac, layout_map, tags, OC_TRIAL_PCE, 1);
                 if (!err)
-                    ac->oc[1].m4ac.chan_config = 0;
+                    ac->oc[1].m4ac.pce = 1;
                 pce_found = 1;
             }
             break;
diff --git a/libavcodec/mpeg4audio.h b/libavcodec/mpeg4audio.h
index 8fd32f96b3..178bef26e2 100644
--- a/libavcodec/mpeg4audio.h
+++ b/libavcodec/mpeg4audio.h
@@ -39,6 +39,7 @@ typedef struct MPEG4AudioConfig {
     int channels;
     int ps;  ///< -1 implicit, 1 presence
     int frame_length_short;
+    int pce;
 } MPEG4AudioConfig;

 extern av_export const int avpriv_mpeg4audio_sample_rates[16];