[FFmpeg-devel] [PATCH] libavfromat/flvenc.c: Preserve the 'amf0' data stream written by Adobe Flash Media Servers while doing a data stream copy

[Benedict Endemann]

From: Benedict Endemann <bendemann at make.tv>

---
 libavformat/flvenc.c |   32 +++++++++++++++++++-------------
 1 file changed, 19 insertions(+), 13 deletions(-)

diff --git a/libavformat/flvenc.c b/libavformat/flvenc.c
index 502da0f..625076a 100644
--- a/libavformat/flvenc.c
+++ b/libavformat/flvenc.c
@@ -225,7 +225,8 @@ static int flv_write_header(AVFormatContext *s)
                 return AVERROR_INVALIDDATA;
             break;
         case AVMEDIA_TYPE_DATA:
-            if (enc->codec_id != AV_CODEC_ID_TEXT) {
+            // 'amf0' is the codec_tag used by the Adobe Flash Media Server for the 'amf0' data packets
+            if (enc->codec_id != AV_CODEC_ID_TEXT && enc->codec_tag != MKTAG('a','m','f','0')) {
                 av_log(s, AV_LOG_ERROR, "Data codec '%s' for stream %d is not compatible with FLV\n",
                        avcodec_get_name(enc->codec_id), i);
                 return AVERROR_INVALIDDATA;
@@ -527,18 +528,23 @@ static int flv_write_packet(AVFormatContext *s, AVPacket *pkt)
     if (enc->codec_type == AVMEDIA_TYPE_DATA) {
         int data_size;
         int metadata_size_pos = avio_tell(pb);
-        avio_w8(pb, AMF_DATA_TYPE_STRING);
-        put_amf_string(pb, "onTextData");
-        avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
-        avio_wb32(pb, 2);
-        put_amf_string(pb, "type");
-        avio_w8(pb, AMF_DATA_TYPE_STRING);
-        put_amf_string(pb, "Text");
-        put_amf_string(pb, "text");
-        avio_w8(pb, AMF_DATA_TYPE_STRING);
-        put_amf_string(pb, pkt->data);
-        put_amf_string(pb, "");
-        avio_w8(pb, AMF_END_OF_OBJECT);
+        if (enc->codec_id == AV_CODEC_ID_TEXT) {
+            avio_w8(pb, AMF_DATA_TYPE_STRING);
+            put_amf_string(pb, "onTextData");
+            avio_w8(pb, AMF_DATA_TYPE_MIXEDARRAY);
+            avio_wb32(pb, 2);
+            put_amf_string(pb, "type");
+            avio_w8(pb, AMF_DATA_TYPE_STRING);
+            put_amf_string(pb, "Text");
+            put_amf_string(pb, "text");
+            avio_w8(pb, AMF_DATA_TYPE_STRING);
+            put_amf_string(pb, pkt->data);
+            put_amf_string(pb, "");
+            avio_w8(pb, AMF_END_OF_OBJECT);
+        }
+        if (enc->codec_tag == MKTAG('a','m','f','0')) {
+        	    avio_write(pb, pkt->data, pkt->size);
+        }
         /* write total size of tag */
         data_size = avio_tell(pb) - metadata_size_pos;
         avio_seek(pb, metadata_size_pos - 10, SEEK_SET);
-- 
1.7.10.4