avcodec/amfdec,rkmppdec: Use correct extradata with BSFs

Otherwise the extradata used would be ISOBMFF if the input is
even though we use the *_mp4toannexb BSFs to convert it to
annex B to feed it to the actual decoder.

(The mediacodec decoders also use said BSFs, yet they process
the extradata in a way that works even when using the ISOBMFF
extradata; in fact, using the converted extradata would break
their check for whether to warn for missing extradata for
the ISOBMFF without-in-band-header profiles.

Furthermore, there are several users of the *_mp4toannexb BSFs
that don't ever touch extradata. They have not been touched.)

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/amfdec.c

@@ -25,6 +25,7 @@
 #include "libavutil/mem.h"
 #include "libavutil/time.h"
 #include "decode.h"
+#include "decode_bsf.h"
 #include "libavutil/mastering_display_metadata.h"
 
 #if CONFIG_D3D11VA
@@ -187,9 +188,12 @@ static int amf_init_decoder(AVCodecContext *avctx)
         AMF_ASSIGN_PROPERTY_INT64(res, ctx->decoder, AMF_VIDEO_DECODER_SURFACE_COPY, ctx->copy_output);
 
     if (avctx->extradata_size) {
-        res = amf_device_ctx->context->pVtbl->AllocBuffer(amf_device_ctx->context, AMF_MEMORY_HOST, avctx->extradata_size, &buffer);
+        const uint8_t *extradata;
+        int extradata_size;
+        ff_decode_get_extradata(avctx, &extradata, &extradata_size);
+        res = amf_device_ctx->context->pVtbl->AllocBuffer(amf_device_ctx->context, AMF_MEMORY_HOST, extradata_size, &buffer);
         if (res == AMF_OK) {
-            memcpy(buffer->pVtbl->GetNative(buffer), avctx->extradata, avctx->extradata_size);
+            memcpy(buffer->pVtbl->GetNative(buffer), extradata, extradata_size);
             AMF_ASSIGN_PROPERTY_INTERFACE(res,ctx->decoder, AMF_VIDEO_DECODER_EXTRADATA, buffer);
             buffer->pVtbl->Release(buffer);
             buffer = NULL;

libavcodec/decode_bsf.h

@@ -0,0 +1,42 @@
+/*
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef AVCODEC_DECODE_BSF_H
+#define AVCODEC_DECODE_BSF_H
+
+#include <stdint.h>
+
+#include "avcodec.h"
+#include "bsf.h"
+#include "internal.h"
+
+/**
+ * Helper function for decoders that may use a BSF that changes extradata.
+ * This function will get the extradata from the BSF.
+ */
+static inline void ff_decode_get_extradata(const AVCodecContext *avctx,
+                                           const uint8_t **extradata,
+                                           int *extradata_size)
+{
+    // Given that we unconditionally insert a null BSF when no BSF is
+    // explicitly requested, we can just use the BSF's par_out here.
+    *extradata      = avctx->internal->bsf->par_out->extradata;
+    *extradata_size = avctx->internal->bsf->par_out->extradata_size;
+}
+
+#endif /* AVCODEC_DECODE_BSF_H */

libavcodec/rkmppdec.c

@@ -29,6 +29,7 @@
 #include "avcodec.h"
 #include "codec_internal.h"
 #include "decode.h"
+#include "decode_bsf.h"
 #include "hwconfig.h"
 #include "libavutil/refstruct.h"
 #include "libavutil/buffer.h"
@@ -279,9 +280,11 @@ static int rkmpp_send_packet(AVCodecContext *avctx, const AVPacket *avpkt)
     // on first packet, send extradata
     if (decoder->first_packet) {
         if (avctx->extradata_size) {
-            ret = rkmpp_write_data(avctx, avctx->extradata,
+            const uint8_t *extradata;
-                                            avctx->extradata_size,
+            int extradata_size;
-                                            avpkt->pts);
+            ff_decode_get_extradata(avctx, &extradata, &extradata_size);
+            ret = rkmpp_write_data(avctx, (uint8_t*)extradata, extradata_size,
+                                   avpkt->pts);
             if (ret) {
                 av_log(avctx, AV_LOG_ERROR, "Failed to write extradata to decoder (code = %d)\n", ret);
                 return ret;