diff --git a/libavcodec/libtheoraenc.c b/libavcodec/libtheoraenc.c
index 431fa57994..364581a4b2 100644
--- a/libavcodec/libtheoraenc.c
+++ b/libavcodec/libtheoraenc.c
@@ -59,21 +59,26 @@ static int concatenate_packet(unsigned int* offset,
     const char* message = NULL;
     uint8_t* newdata    = NULL;
     int newsize = avc_context->extradata_size + 2 + packet->bytes;
+    int ret;
 
     if (packet->bytes < 0) {
         message = "ogg_packet has negative size";
+        ret = AVERROR_INVALIDDATA;
     } else if (packet->bytes > 0xffff) {
         message = "ogg_packet is larger than 65535 bytes";
+        ret = AVERROR_INVALIDDATA;
     } else if (newsize < avc_context->extradata_size) {
         message = "extradata_size would overflow";
+        ret = AVERROR_INVALIDDATA;
     } else {
         newdata = av_realloc(avc_context->extradata, newsize);
         if (!newdata)
             message = "av_realloc failed";
+        ret = AVERROR(ENOMEM);
     }
     if (message) {
         av_log(avc_context, AV_LOG_ERROR, "concatenate_packet failed: %s\n", message);
-        return -1;
+        return ret;
     }
 
     avc_context->extradata      = newdata;
@@ -95,7 +100,7 @@ static int get_stats(AVCodecContext *avctx, int eos)
     bytes = th_encode_ctl(h->t_state, TH_ENCCTL_2PASS_OUT, &buf, sizeof(buf));
     if (bytes < 0) {
         av_log(avctx, AV_LOG_ERROR, "Error getting first pass stats\n");
-        return -1;
+        return AVERROR_EXTERNAL;
     }
     if (!eos) {
         h->stats = av_fast_realloc(h->stats, &h->stats_size,
@@ -112,7 +117,7 @@ static int get_stats(AVCodecContext *avctx, int eos)
     return 0;
 #else
     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
-    return -1;
+    return AVERROR(ENOSUP);
 #endif
 }
 
@@ -126,7 +131,7 @@ static int submit_stats(AVCodecContext *avctx)
     if (!h->stats) {
         if (!avctx->stats_in) {
             av_log(avctx, AV_LOG_ERROR, "No statsfile for second pass\n");
-            return -1;
+            return AVERROR(EINVAL);
         }
         h->stats_size = strlen(avctx->stats_in) * 3/4;
         h->stats      = av_malloc(h->stats_size);
@@ -138,7 +143,7 @@ static int submit_stats(AVCodecContext *avctx)
                               h->stats_size - h->stats_offset);
         if (bytes < 0) {
             av_log(avctx, AV_LOG_ERROR, "Error submitting stats\n");
-            return -1;
+            return AVERROR_EXTERNAL;
         }
         if (!bytes)
             return 0;
@@ -147,7 +152,7 @@ static int submit_stats(AVCodecContext *avctx)
     return 0;
 #else
     av_log(avctx, AV_LOG_ERROR, "libtheora too old to support 2pass\n");
-    return -1;
+    return AVERROR(ENOSUP);
 #endif
 }
 
@@ -159,6 +164,7 @@ static av_cold int encode_init(AVCodecContext* avc_context)
     unsigned int offset;
     TheoraContext *h = avc_context->priv_data;
     uint32_t gop_size = avc_context->gop_size;
+    int ret;
 
     /* Set up the theora_info struct */
     th_info_init(&t_info);
@@ -195,7 +201,7 @@ static av_cold int encode_init(AVCodecContext* avc_context)
         t_info.pixel_fmt = TH_PF_444;
     else {
         av_log(avc_context, AV_LOG_ERROR, "Unsupported pix_fmt\n");
-        return -1;
+        return AVERROR(EINVAL);
     }
     avcodec_get_chroma_sub_sample(avc_context->pix_fmt, &h->uv_hshift, &h->uv_vshift);
 
@@ -216,7 +222,7 @@ static av_cold int encode_init(AVCodecContext* avc_context)
     h->t_state = th_encode_alloc(&t_info);
     if (!h->t_state) {
         av_log(avc_context, AV_LOG_ERROR, "theora_encode_init failed\n");
-        return -1;
+        return AVERROR_EXTERNAL;
     }
 
     h->keyframe_mask = (1 << t_info.keyframe_granule_shift) - 1;
@@ -226,16 +232,16 @@ static av_cold int encode_init(AVCodecContext* avc_context)
     if (th_encode_ctl(h->t_state, TH_ENCCTL_SET_KEYFRAME_FREQUENCY_FORCE,
                       &gop_size, sizeof(gop_size))) {
         av_log(avc_context, AV_LOG_ERROR, "Error setting GOP size\n");
-        return -1;
+        return AVERROR_EXTERNAL;
     }
 
     // need to enable 2 pass (via TH_ENCCTL_2PASS_) before encoding headers
     if (avc_context->flags & CODEC_FLAG_PASS1) {
-        if (get_stats(avc_context, 0))
-            return -1;
+        if ((ret = get_stats(avc_context, 0)) < 0)
+            return ret;
     } else if (avc_context->flags & CODEC_FLAG_PASS2) {
-        if (submit_stats(avc_context))
-            return -1;
+        if ((ret = submit_stats(avc_context)) < 0)
+            return ret;
     }
 
     /*
@@ -251,8 +257,8 @@ static av_cold int encode_init(AVCodecContext* avc_context)
     th_comment_init(&t_comment);
 
     while (th_encode_flushheader(h->t_state, &t_comment, &o_packet))
-        if (concatenate_packet(&offset, avc_context, &o_packet))
-            return -1;
+        if ((ret = concatenate_packet(&offset, avc_context, &o_packet)) < 0)
+            return ret;
 
     th_comment_clear(&t_comment);
 
@@ -274,8 +280,8 @@ static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
     if (!frame) {
         th_encode_packetout(h->t_state, 1, &o_packet);
         if (avc_context->flags & CODEC_FLAG_PASS1)
-            if (get_stats(avc_context, 1))
-                return -1;
+            if ((ret = get_stats(avc_context, 1)) < 0)
+                return ret;
         return 0;
     }
 
@@ -288,8 +294,8 @@ static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
     }
 
     if (avc_context->flags & CODEC_FLAG_PASS2)
-        if (submit_stats(avc_context))
-            return -1;
+        if ((ret = submit_stats(avc_context)) < 0)
+            return ret;
 
     /* Now call into theora_encode_YUVin */
     result = th_encode_ycbcr_in(h->t_state, t_yuv_buffer);
@@ -307,12 +313,12 @@ static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
             break;
         }
         av_log(avc_context, AV_LOG_ERROR, "theora_encode_YUVin failed (%s) [%d]\n", message, result);
-        return -1;
+        return AVERROR_EXTERNAL;
     }
 
     if (avc_context->flags & CODEC_FLAG_PASS1)
-        if (get_stats(avc_context, 0))
-            return -1;
+        if ((ret = get_stats(avc_context, 0)) < 0)
+            return ret;
 
     /* Pick up returned ogg_packet */
     result = th_encode_packetout(h->t_state, 0, &o_packet);
@@ -325,7 +331,7 @@ static int encode_frame(AVCodecContext* avc_context, AVPacket *pkt,
         break;
     default:
         av_log(avc_context, AV_LOG_ERROR, "theora_encode_packetout failed [%d]\n", result);
-        return -1;
+        return AVERROR_EXTERNAL;
     }
 
     /* Copy ogg_packet content out to buffer */