@@ -1762,7 +1762,7 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)

     if (!avctx->extradata || (avctx->extradata_size < 48)) {

         av_log(avctx, AV_LOG_ERROR, "extradata missing or truncated\n");

-        return -1;

+        return AVERROR_INVALIDDATA;

     }

     extradata      = avctx->extradata;

@@ -1778,18 +1778,18 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)

     if (extradata_size < 12) {

         av_log(avctx, AV_LOG_ERROR, "not enough extradata (%i)\n",

                extradata_size);

-        return -1;

+        return AVERROR_INVALIDDATA;

     }

     if (memcmp(extradata, "frmaQDM", 7)) {

         av_log(avctx, AV_LOG_ERROR, "invalid headers, QDM? not found\n");

-        return -1;

+        return AVERROR_INVALIDDATA;

     }

     if (extradata[7] == 'C') {

 //        s->is_qdmc = 1;

-        av_log(avctx, AV_LOG_ERROR, "stream is QDMC version 1, which is not supported\n");

-        return -1;

+        avpriv_report_missing_feature(avctx, "QDMC version 1");

+        return AVERROR_PATCHWELCOME;

     }

     extradata += 8;

@@ -1800,14 +1800,14 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)

     if(size > extradata_size){

         av_log(avctx, AV_LOG_ERROR, "extradata size too small, %i < %i\n",

                extradata_size, size);

-        return -1;

+        return AVERROR_INVALIDDATA;

     }

     extradata += 4;

     av_log(avctx, AV_LOG_DEBUG, "size: %d\n", size);

     if (AV_RB32(extradata) != MKBETAG('Q','D','C','A')) {

         av_log(avctx, AV_LOG_ERROR, "invalid extradata, expecting QDCA\n");

-        return -1;

+        return AVERROR_INVALIDDATA;

     }

     extradata += 8;

@@ -1882,8 +1882,8 @@ static av_cold int qdm2_decode_init(AVCodecContext *avctx)

     // Fail on unknown fft order

     if ((s->fft_order < 7) || (s->fft_order > 9)) {

-        av_log(avctx, AV_LOG_ERROR, "Unknown FFT order (%d), contact the developers!\n", s->fft_order);

-        return -1;

+        avpriv_request_sample(avctx, "Unknown FFT order %d", s->fft_order);

+        return AVERROR_PATCHWELCOME;

     }

     if (s->fft_size != (1 << (s->fft_order - 1))) {

         av_log(avctx, AV_LOG_ERROR, "FFT size %d not power of 2.\n", s->fft_size);

@@ -1990,8 +1990,8 @@ static int qdm2_decode_frame(AVCodecContext *avctx, void *data,

     out = (int16_t *)frame->data[0];

     for (i = 0; i < 16; i++) {

-        if (qdm2_decode(s, buf, out) < 0)

-            return -1;

+        if ((ret = qdm2_decode(s, buf, out)) < 0)

+            return ret;

         out += s->channels * s->frame_size;

     }