From 50e0e96f3f8ed57443707289a621446cef0fe367 Mon Sep 17 00:00:00 2001
From: James Almer <jamrial@gmail.com>
Date: Fri, 18 Nov 2016 12:21:54 -0300
Subject: [PATCH] avformat/apngenc: use the stream parameters extradata if
 available

Fixes remuxing apng streams coming from the apng demuxer, which sends extradata
during init.

Signed-off-by: James Almer <jamrial@gmail.com>
---
 libavformat/apngenc.c    | 9 +++++++++
 tests/lavf-regression.sh | 6 +++---
 tests/ref/lavf/apng      | 3 +++
 3 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/libavformat/apngenc.c b/libavformat/apngenc.c
index e5e8aa998f..0c40be297f 100644
--- a/libavformat/apngenc.c
+++ b/libavformat/apngenc.c
@@ -81,6 +81,7 @@ static void apng_write_chunk(AVIOContext *io_context, uint32_t tag,
 static int apng_write_header(AVFormatContext *format_context)
 {
     APNGMuxContext *apng = format_context->priv_data;
+    AVCodecParameters *par = format_context->streams[0]->codecpar;
 
     if (format_context->nb_streams != 1 ||
         format_context->streams[0]->codecpar->codec_type != AVMEDIA_TYPE_VIDEO ||
@@ -101,6 +102,14 @@ static int apng_write_header(AVFormatContext *format_context)
     avio_wb64(format_context->pb, PNGSIG);
     // Remaining headers are written when they are copied from the encoder
 
+    if (par->extradata_size) {
+        apng->extra_data = av_mallocz(par->extradata_size + AV_INPUT_BUFFER_PADDING_SIZE);
+        if (!apng->extra_data)
+            return AVERROR(ENOMEM);
+        apng->extra_data_size = par->extradata_size;
+        memcpy(apng->extra_data, par->extradata, par->extradata_size);
+    }
+
     return 0;
 }
 
diff --git a/tests/lavf-regression.sh b/tests/lavf-regression.sh
index e47be1854b..12954d5044 100755
--- a/tests/lavf-regression.sh
+++ b/tests/lavf-regression.sh
@@ -216,9 +216,9 @@ if [ -n "$do_apng" ] ; then
 file=${outfile}lavf.apng
 do_avconv $file $DEC_OPTS -f image2 -vcodec pgmyuv -i $raw_src $ENC_OPTS -t 1 -pix_fmt rgb24
 do_avconv_crc $file $DEC_OPTS -i $target_path/$file -pix_fmt rgb24
-#file_copy=${outfile}lavf.copy.apng
-#do_avconv $file_copy $DEC_OPTS -i $file $ENC_OPTS -c copy
-#do_avconv_crc $file_copy $DEC_OPTS -i $target_path/$file_copy
+file_copy=${outfile}lavf.copy.apng
+do_avconv $file_copy $DEC_OPTS -i $file $ENC_OPTS -c copy
+do_avconv_crc $file_copy $DEC_OPTS -i $target_path/$file_copy
 file=${outfile}lavf.png
 do_avconv $file $DEC_OPTS -f image2 -vcodec pgmyuv -i $raw_src $ENC_OPTS -pix_fmt rgb24 -frames:v 1 -f apng
 do_avconv_crc $file $DEC_OPTS -i $target_path/$file -pix_fmt rgb24
diff --git a/tests/ref/lavf/apng b/tests/ref/lavf/apng
index 4d354089ab..8e9e5e6b73 100644
--- a/tests/ref/lavf/apng
+++ b/tests/ref/lavf/apng
@@ -1,6 +1,9 @@
 a4c46fad7716ad094eb3c78b74ca0244 *./tests/data/lavf/lavf.apng
 6209864 ./tests/data/lavf/lavf.apng
 ./tests/data/lavf/lavf.apng CRC=0x87b3c15f
+a4c46fad7716ad094eb3c78b74ca0244 *./tests/data/lavf/lavf.copy.apng
+6209864 ./tests/data/lavf/lavf.copy.apng
+./tests/data/lavf/lavf.copy.apng CRC=0x87b3c15f
 c5900fdd1b2fc30b985793f5226fd0c4 *./tests/data/lavf/lavf.png
 248854 ./tests/data/lavf/lavf.png
 ./tests/data/lavf/lavf.png CRC=0xd8c7b7a1