rtpdec: Use .init instead of .alloc to set default values

The ugly error handling in rdt gets improved in a later commit.
Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/rdt.c

@@ -298,6 +298,9 @@ rdt_parse_packet (AVFormatContext *ctx, PayloadContext *rdt, AVStream *st,
     int seq = 1, res;
     AVIOContext pb;
 
+    if (!rdt->rmctx)
+        return AVERROR(EINVAL);
+
     if (rdt->audio_pkt_cnt == 0) {
         int pos;
 
@@ -521,20 +524,9 @@ ff_real_parse_sdp_a_line (AVFormatContext *s, int stream_index,
         real_parse_asm_rulebook(s, s->streams[stream_index], p);
 }
 
-static PayloadContext *
-rdt_new_context (void)
+static av_cold int rdt_init(AVFormatContext *s, int st_index, PayloadContext *rdt)
 {
-    PayloadContext *rdt = av_mallocz(sizeof(PayloadContext));
-    int ret;
-    if (!rdt)
-        return NULL;
-    ret = avformat_open_input(&rdt->rmctx, "", &ff_rdt_demuxer, NULL);
-    if (ret < 0) {
-        av_free(rdt);
-        return NULL;
-    }
-
-    return rdt;
+    return avformat_open_input(&rdt->rmctx, "", &ff_rdt_demuxer, NULL);
 }
 
 static void
@@ -559,8 +551,9 @@ static RTPDynamicProtocolHandler rdt_ ## n ## _handler = { \
     .enc_name         = s, \
     .codec_type       = t, \
     .codec_id         = AV_CODEC_ID_NONE, \
+    .priv_data_size   = sizeof(PayloadContext), \
+    .init             = rdt_init, \
     .parse_sdp_a_line = rdt_parse_sdp_line, \
-    .alloc            = rdt_new_context, \
     .free             = rdt_free_context, \
     .parse_packet     = rdt_parse_packet \
 }

libavformat/rtpdec_amr.c

@@ -38,13 +38,10 @@ struct PayloadContext {
     int channels;
 };
 
-static PayloadContext *amr_new_context(void)
+static av_cold int amr_init(AVFormatContext *s, int st_index, PayloadContext *data)
 {
-    PayloadContext *data = av_mallocz(sizeof(PayloadContext));
-    if (!data)
-        return data;
     data->channels = 1;
-    return data;
+    return 0;
 }
 
 static int amr_handle_packet(AVFormatContext *ctx, PayloadContext *data,
@@ -189,8 +186,9 @@ RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler = {
     .enc_name         = "AMR",
     .codec_type       = AVMEDIA_TYPE_AUDIO,
     .codec_id         = AV_CODEC_ID_AMR_NB,
+    .priv_data_size   = sizeof(PayloadContext),
+    .init             = amr_init,
     .parse_sdp_a_line = amr_parse_sdp_line,
-    .alloc            = amr_new_context,
     .parse_packet     = amr_handle_packet,
 };
 
@@ -198,7 +196,8 @@ RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler = {
     .enc_name         = "AMR-WB",
     .codec_type       = AVMEDIA_TYPE_AUDIO,
     .codec_id         = AV_CODEC_ID_AMR_WB,
+    .priv_data_size   = sizeof(PayloadContext),
+    .init             = amr_init,
     .parse_sdp_a_line = amr_parse_sdp_line,
-    .alloc            = amr_new_context,
     .parse_packet     = amr_handle_packet,
 };

libavformat/rtpdec_vp8.c

@@ -269,13 +269,10 @@ static int vp8_handle_packet(AVFormatContext *ctx, PayloadContext *vp8,
     return AVERROR(EAGAIN);
 }
 
-static PayloadContext *vp8_new_context(void)
+static av_cold int vp8_init(AVFormatContext *s, int st_index, PayloadContext *vp8)
 {
-    PayloadContext *vp8 = av_mallocz(sizeof(PayloadContext));
-    if (!vp8)
-        return NULL;
     vp8->sequence_ok = 1;
-    return vp8;
+    return 0;
 }
 
 static void vp8_free_context(PayloadContext *vp8)
@@ -293,7 +290,8 @@ RTPDynamicProtocolHandler ff_vp8_dynamic_handler = {
     .enc_name       = "VP8",
     .codec_type     = AVMEDIA_TYPE_VIDEO,
     .codec_id       = AV_CODEC_ID_VP8,
-    .alloc          = vp8_new_context,
+    .priv_data_size = sizeof(PayloadContext),
+    .init           = vp8_init,
     .free           = vp8_free_context,
     .parse_packet   = vp8_handle_packet,
     .need_keyframe  = vp8_need_keyframe,