[FFmpeg-devel] [PATCH] avformat/matroskadec: Parse encryption init info from streams.

[Jacob Trimble]

Signed-off-by: Jacob Trimble <modmaker at google.com>
---
 libavformat/matroskadec.c | 43 +++++++++++++++++++++++++++++----------
 1 file changed, 32 insertions(+), 11 deletions(-)

diff --git a/libavformat/matroskadec.c b/libavformat/matroskadec.c
index 1ded431b80..bfef329e59 100644
--- a/libavformat/matroskadec.c
+++ b/libavformat/matroskadec.c
@@ -2080,7 +2080,8 @@ static int matroska_parse_tracks(AVFormatContext *s)
         int extradata_offset = 0;
         uint32_t fourcc = 0;
         AVIOContext b;
-        char* key_id_base64 = NULL;
+        char* key_id = NULL;
+        int key_id_size = 0;
         int bit_depth = -1;
 
         /* Apply some sanity checks. */
@@ -2133,14 +2134,8 @@ static int matroska_parse_tracks(AVFormatContext *s)
                 if (encodings[0].encryption.key_id.size > 0) {
                     /* Save the encryption key id to be stored later as a
                        metadata tag. */
-                    const int b64_size = AV_BASE64_SIZE(encodings[0].encryption.key_id.size);
-                    key_id_base64 = av_malloc(b64_size);
-                    if (key_id_base64 == NULL)
-                        return AVERROR(ENOMEM);
-
-                    av_base64_encode(key_id_base64, b64_size,
-                                     encodings[0].encryption.key_id.data,
-                                     encodings[0].encryption.key_id.size);
+                    key_id = encodings[0].encryption.key_id.data;
+                    key_id_size = encodings[0].encryption.key_id.size;
                 } else {
                     encodings[0].scope = 0;
                     av_log(matroska->ctx, AV_LOG_ERROR,
@@ -2198,14 +2193,40 @@ static int matroska_parse_tracks(AVFormatContext *s)
 
         st = track->stream = avformat_new_stream(s, NULL);
         if (!st) {
-            av_free(key_id_base64);
             return AVERROR(ENOMEM);
         }
 
-        if (key_id_base64) {
+        if (key_id) {
+            AVEncryptionInitInfo *init_info;
+            uint8_t *side_data;
+            size_t side_data_size;
+            const int b64_size = AV_BASE64_SIZE(key_id_size);
+            char *key_id_base64 = av_malloc(b64_size);
+            if (!key_id_base64)
+                return AVERROR(ENOMEM);
+            av_base64_encode(key_id_base64, b64_size, key_id, key_id_size);
+
             /* export encryption key id as base64 metadata tag */
             av_dict_set(&st->metadata, "enc_key_id", key_id_base64, 0);
             av_freep(&key_id_base64);
+
+
+            /* Convert the key ID to a generic encryption init info */
+            init_info = av_encryption_init_info_alloc(/* system_id_size */ 0, /* num_key_ids */ 1,
+                                                      /* key_id_size */ key_id_size, /* data_size */ 0);
+            if (!init_info)
+                return AVERROR(ENOMEM);
+            memcpy(init_info->key_ids[0], key_id, key_id_size);
+            side_data = av_encryption_init_info_add_side_data(init_info, &side_data_size);
+            av_encryption_init_info_free(init_info);
+            if (!side_data)
+                return AVERROR(ENOMEM);
+            ret = av_stream_add_side_data(st, AV_PKT_DATA_ENCRYPTION_INIT_INFO,
+                                          side_data, side_data_size);
+            if (ret < 0) {
+                av_free(side_data);
+                return ret;
+            }
         }
 
         if (!strcmp(track->codec_id, "V_MS/VFW/FOURCC") &&
-- 
2.18.0.203.gfac676dfb9-goog