rtpdec: Split handling of mpeg12 audio/video to a separate depacketizer

This also adds checking of mallocs.

Signed-off-by: Martin Storsjö <martin@martin.st>

libavformat/Makefile

@@ -34,6 +34,7 @@ OBJS-$(CONFIG_RTPDEC)                    += rdt.o                       \
                                             rtpdec_ilbc.o               \
                                             rtpdec_jpeg.o               \
                                             rtpdec_latm.o               \
+                                            rtpdec_mpeg12.o             \
                                             rtpdec_mpeg4.o              \
                                             rtpdec_mpegts.o             \
                                             rtpdec_qcelp.o              \

libavformat/rtpdec.c

@@ -74,6 +74,8 @@ void av_register_rtp_dynamic_payload_handlers(void)
     ff_register_dynamic_payload_handler(&ff_jpeg_dynamic_handler);
     ff_register_dynamic_payload_handler(&ff_mp4a_latm_dynamic_handler);
     ff_register_dynamic_payload_handler(&ff_mp4v_es_dynamic_handler);
+    ff_register_dynamic_payload_handler(&ff_mpeg_audio_dynamic_handler);
+    ff_register_dynamic_payload_handler(&ff_mpeg_video_dynamic_handler);
     ff_register_dynamic_payload_handler(&ff_mpeg4_generic_dynamic_handler);
     ff_register_dynamic_payload_handler(&ff_mpegts_dynamic_handler);
     ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfv_handler);
@@ -583,7 +585,7 @@ static void finalize_packet(RTPDemuxContext *s, AVPacket *pkt, uint32_t timestam
 static int rtp_parse_packet_internal(RTPDemuxContext *s, AVPacket *pkt,
                                      const uint8_t *buf, int len)
 {
-    unsigned int ssrc, h;
+    unsigned int ssrc;
     int payload_type, seq, flags = 0;
     int ext;
     AVStream *st;
@@ -645,42 +647,8 @@ static int rtp_parse_packet_internal(RTPDemuxContext *s, AVPacket *pkt,
     } else if (st) {
         /* At this point, the RTP header has been stripped;
          * This is ASSUMING that there is only 1 CSRC, which isn't wise. */
-        switch (st->codec->codec_id) {
-        case AV_CODEC_ID_MP2:
-        case AV_CODEC_ID_MP3:
-            /* better than nothing: skip MPEG audio RTP header */
-            if (len <= 4)
-                return -1;
-            h    = AV_RB32(buf);
-            len -= 4;
-            buf += 4;
-            av_new_packet(pkt, len);
-            memcpy(pkt->data, buf, len);
-            break;
-        case AV_CODEC_ID_MPEG1VIDEO:
-        case AV_CODEC_ID_MPEG2VIDEO:
-            /* better than nothing: skip MPEG video RTP header */
-            if (len <= 4)
-                return -1;
-            h    = AV_RB32(buf);
-            buf += 4;
-            len -= 4;
-            if (h & (1 << 26)) {
-                /* MPEG-2 */
-                if (len <= 4)
-                    return -1;
-                buf += 4;
-                len -= 4;
-            }
-            av_new_packet(pkt, len);
-            memcpy(pkt->data, buf, len);
-            break;
-        default:
-            av_new_packet(pkt, len);
-            memcpy(pkt->data, buf, len);
-            break;
-        }
-
+        av_new_packet(pkt, len);
+        memcpy(pkt->data, buf, len);
         pkt->stream_index = st->index;
     } else {
         return AVERROR(EINVAL);

libavformat/rtpdec_formats.h

@@ -49,6 +49,8 @@ extern RTPDynamicProtocolHandler ff_ilbc_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_jpeg_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_mp4a_latm_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_mp4v_es_dynamic_handler;
+extern RTPDynamicProtocolHandler ff_mpeg_audio_dynamic_handler;
+extern RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_mpeg4_generic_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_mpegts_dynamic_handler;
 extern RTPDynamicProtocolHandler ff_ms_rtp_asf_pfa_handler;

libavformat/rtpdec_mpeg12.c

@@ -0,0 +1,62 @@
+/*
+ * Common code for the RTP depacketization of MPEG-1/2 formats.
+ * Copyright (c) 2002 Fabrice Bellard
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "rtpdec_formats.h"
+#include "libavutil/intreadwrite.h"
+
+static int mpeg_parse_packet(AVFormatContext *ctx, PayloadContext *data,
+                             AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                             const uint8_t *buf, int len, uint16_t seq,
+                             int flags)
+{
+    unsigned int h;
+    if (len <= 4)
+        return AVERROR_INVALIDDATA;
+    h    = AV_RB32(buf);
+    buf += 4;
+    len -= 4;
+    if (st->codec->codec_type == AVMEDIA_TYPE_VIDEO && h & (1 << 26)) {
+        /* MPEG-2 */
+        if (len <= 4)
+            return AVERROR_INVALIDDATA;
+        buf += 4;
+        len -= 4;
+    }
+    if (av_new_packet(pkt, len) < 0)
+        return AVERROR(ENOMEM);
+    memcpy(pkt->data, buf, len);
+    pkt->stream_index = st->index;
+    return 0;
+}
+
+RTPDynamicProtocolHandler ff_mpeg_audio_dynamic_handler = {
+    .codec_type        = AVMEDIA_TYPE_AUDIO,
+    .codec_id          = AV_CODEC_ID_MP3,
+    .parse_packet      = mpeg_parse_packet,
+    .static_payload_id = 14,
+};
+
+RTPDynamicProtocolHandler ff_mpeg_video_dynamic_handler = {
+    .codec_type        = AVMEDIA_TYPE_VIDEO,
+    .codec_id          = AV_CODEC_ID_MPEG2VIDEO,
+    .parse_packet      = mpeg_parse_packet,
+    .static_payload_id = 32,
+};