From 27085d1b47c3741cc0fac284c916127c4066d049 Mon Sep 17 00:00:00 2001
From: Anton Khirnov <anton@khirnov.net>
Date: Sat, 1 Oct 2016 21:07:42 +0200
Subject: [PATCH] avconv: only retry decoding on actual decoding errors

Errors during decoding are currently considered non-fatal and do not
terminate transcoding, so even if parts of the data are corrupted, the
rest may be decodable.

However, that should apply only to the actual decoding calls, not to the
failures elsewhere (e.g. configuring filters).
---
 avconv.c | 37 +++++++++++++++++++++++++++----------
 1 file changed, 27 insertions(+), 10 deletions(-)

diff --git a/avconv.c b/avconv.c
index 87923b9825..0b75cbe214 100644
--- a/avconv.c
+++ b/avconv.c
@@ -1326,7 +1326,8 @@ int guess_input_channel_layout(InputStream *ist)
     return 1;
 }
 
-static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output)
+static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output,
+                        int *decode_failed)
 {
     AVFrame *decoded_frame, *f;
     AVCodecContext *avctx = ist->dec_ctx;
@@ -1339,6 +1340,8 @@ static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output)
     decoded_frame = ist->decoded_frame;
 
     ret = decode(avctx, decoded_frame, got_output, pkt);
+    if (ret < 0)
+        *decode_failed = 1;
     if (!*got_output || ret < 0)
         return ret;
 
@@ -1377,7 +1380,8 @@ static int decode_audio(InputStream *ist, AVPacket *pkt, int *got_output)
     return err < 0 ? err : ret;
 }
 
-static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output)
+static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output,
+                        int *decode_failed)
 {
     AVFrame *decoded_frame, *f;
     int i, ret = 0, err = 0;
@@ -1389,6 +1393,8 @@ static int decode_video(InputStream *ist, AVPacket *pkt, int *got_output)
     decoded_frame = ist->decoded_frame;
 
     ret = decode(ist->dec_ctx, decoded_frame, got_output, pkt);
+    if (ret < 0)
+        *decode_failed = 1;
     if (!*got_output || ret < 0)
         return ret;
 
@@ -1429,13 +1435,16 @@ fail:
     return err < 0 ? err : ret;
 }
 
-static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output)
+static int transcode_subtitles(InputStream *ist, AVPacket *pkt, int *got_output,
+                               int *decode_failed)
 {
     AVSubtitle subtitle;
     int i, ret = avcodec_decode_subtitle2(ist->dec_ctx,
                                           &subtitle, got_output, pkt);
-    if (ret < 0)
+    if (ret < 0) {
+        *decode_failed = 1;
         return ret;
+    }
     if (!*got_output)
         return ret;
 
@@ -1491,16 +1500,19 @@ static void process_input_packet(InputStream *ist, const AVPacket *pkt, int no_e
     while (ist->decoding_needed && (!pkt || avpkt.size > 0)) {
         int ret = 0;
         int got_output = 0;
+        int decode_failed = 0;
 
         if (!repeating)
             ist->last_dts = ist->next_dts;
 
         switch (ist->dec_ctx->codec_type) {
         case AVMEDIA_TYPE_AUDIO:
-            ret = decode_audio    (ist, repeating ? NULL : &avpkt, &got_output);
+            ret = decode_audio    (ist, repeating ? NULL : &avpkt, &got_output,
+                                   &decode_failed);
             break;
         case AVMEDIA_TYPE_VIDEO:
-            ret = decode_video    (ist, repeating ? NULL : &avpkt, &got_output);
+            ret = decode_video    (ist, repeating ? NULL : &avpkt, &got_output,
+                                   &decode_failed);
             if (repeating && !got_output)
                 ;
             else if (pkt && pkt->duration)
@@ -1517,16 +1529,21 @@ static void process_input_packet(InputStream *ist, const AVPacket *pkt, int no_e
         case AVMEDIA_TYPE_SUBTITLE:
             if (repeating)
                 break;
-            ret = transcode_subtitles(ist, &avpkt, &got_output);
+            ret = transcode_subtitles(ist, &avpkt, &got_output, &decode_failed);
             break;
         default:
             return;
         }
 
         if (ret < 0) {
-            av_log(NULL, AV_LOG_ERROR, "Error while decoding stream #%d:%d\n",
-                   ist->file_index, ist->st->index);
-            if (exit_on_error)
+            if (decode_failed) {
+                av_log(NULL, AV_LOG_ERROR, "Error while decoding stream #%d:%d\n",
+                       ist->file_index, ist->st->index);
+            } else {
+                av_log(NULL, AV_LOG_FATAL, "Error while processing the decoded "
+                       "data for stream #%d:%d\n", ist->file_index, ist->st->index);
+            }
+            if (!decode_failed || exit_on_error)
                 exit_program(1);
             break;
         }