avcodec/omx: ensure zerocopy mode can be disabled on rpi builds

fixes https://trac.ffmpeg.org/ticket/6586Signed-off-by: Aman Gupta <aman@tmm1.net>

libavcodec/omx.c

@@ -644,10 +644,6 @@ static av_cold int omx_encode_init(AVCodecContext *avctx)
     OMX_BUFFERHEADERTYPE *buffer;
     OMX_ERRORTYPE err;
 
-#if CONFIG_OMX_RPI
-    s->input_zerocopy = 1;
-#endif
-
     s->omx_context = omx_init(avctx, s->libname, s->libprefix);
     if (!s->omx_context)
         return AVERROR_ENCODER_NOT_FOUND;
@@ -933,7 +929,7 @@ static av_cold int omx_encode_end(AVCodecContext *avctx)
 static const AVOption options[] = {
     { "omx_libname", "OpenMAX library name", OFFSET(libname), AV_OPT_TYPE_STRING, { 0 }, 0, 0, VDE },
     { "omx_libprefix", "OpenMAX library prefix", OFFSET(libprefix), AV_OPT_TYPE_STRING, { 0 }, 0, 0, VDE },
-    { "zerocopy", "Try to avoid copying input frames if possible", OFFSET(input_zerocopy), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, VE },
+    { "zerocopy", "Try to avoid copying input frames if possible", OFFSET(input_zerocopy), AV_OPT_TYPE_INT, { .i64 = CONFIG_OMX_RPI }, 0, 1, VE },
     { "profile",  "Set the encoding profile", OFFSET(profile), AV_OPT_TYPE_INT,   { .i64 = FF_PROFILE_UNKNOWN },       FF_PROFILE_UNKNOWN, FF_PROFILE_H264_HIGH, VE, "profile" },
     { "baseline", "",                         0,               AV_OPT_TYPE_CONST, { .i64 = FF_PROFILE_H264_BASELINE }, 0, 0, VE, "profile" },
     { "main",     "",                         0,               AV_OPT_TYPE_CONST, { .i64 = FF_PROFILE_H264_MAIN },     0, 0, VE, "profile" },