[FFmpeg-devel] [PATCH v1] avcodec/h264_parse: decode sps before pps

[Jun Li]

Fix ticket #6422
The content put pps before sps, which is not a common case. The change
just put decoding sps before pps, just for compability.

Signed-off-by: Jun Li <junli1026 at gmail.com>
---
 libavcodec/h264_parse.c | 21 +++++++++++----------
 1 file changed, 11 insertions(+), 10 deletions(-)

diff --git a/libavcodec/h264_parse.c b/libavcodec/h264_parse.c
index 352ffea948..26aaa751ad 100644
--- a/libavcodec/h264_parse.c
+++ b/libavcodec/h264_parse.c
@@ -373,35 +373,36 @@ static int decode_extradata_ps(const uint8_t *data, int size, H264ParamSets *ps,
         goto fail;
     }
 
-    for (i = 0; i < pkt.nb_nals; i++) {
+    /* decode sps before pps, just in case some bitstream put pps before sps. */
+    for(i = 0; i < pkt.nb_nals; i++) {
         H2645NAL *nal = &pkt.nals[i];
-        switch (nal->type) {
-        case H264_NAL_SPS: {
+        if (nal->type == H264_NAL_SPS) {
             GetBitContext tmp_gb = nal->gb;
             ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps, 0);
             if (ret >= 0)
-                break;
+                continue;
             av_log(logctx, AV_LOG_DEBUG,
                    "SPS decoding failure, trying again with the complete NAL\n");
             init_get_bits8(&tmp_gb, nal->raw_data + 1, nal->raw_size - 1);
             ret = ff_h264_decode_seq_parameter_set(&tmp_gb, logctx, ps, 0);
             if (ret >= 0)
-                break;
+                continue;
             ret = ff_h264_decode_seq_parameter_set(&nal->gb, logctx, ps, 1);
             if (ret < 0)
                 goto fail;
-            break;
         }
-        case H264_NAL_PPS:
+    }
+
+    for (i = 0; i < pkt.nb_nals; i++) {
+        H2645NAL *nal = &pkt.nals[i];
+        if (nal->type == H264_NAL_PPS) {
             ret = ff_h264_decode_picture_parameter_set(&nal->gb, logctx, ps,
                                                        nal->size_bits);
             if (ret < 0)
                 goto fail;
-            break;
-        default:
+        } else if (nal->type != H264_NAL_SPS) {
             av_log(logctx, AV_LOG_VERBOSE, "Ignoring NAL type %d in extradata\n",
                    nal->type);
-            break;
         }
     }
 
-- 
2.17.1