Add a Vorbis payload parser. Implemented by Colin McQuillan as a GSoC

qualification task, see "RTP/Vorbis payload implementation (GSoC qual
task)" thread on mailinglist.

Originally committed as revision 18509 to svn://svn.ffmpeg.org/ffmpeg/trunk

Changelog

@@ -8,6 +8,7 @@ version <next>:
 - PCX encoder
 - RTP packetization of H.263
 - RTP packetization of AMR
+- RTP depacketization of Vorbis
 
 
 

libavformat/Makefile

@@ -196,7 +196,7 @@ OBJS-$(CONFIG_RTP_MUXER)                 += rtp.o         \
                                             rtpenc_h264.o \
                                             avc.o
 OBJS-$(CONFIG_RTSP_DEMUXER)              += rdt.o rtsp.o
-OBJS-$(CONFIG_SDP_DEMUXER)               += rtsp.o rtp.o rtpdec.o rtp_h264.o
+OBJS-$(CONFIG_SDP_DEMUXER)               += rtsp.o rtp.o rtpdec.o rtp_h264.o rtp_vorbis.o
 OBJS-$(CONFIG_SEGAFILM_DEMUXER)          += segafilm.o
 OBJS-$(CONFIG_SHORTEN_DEMUXER)           += raw.o id3v2.o
 OBJS-$(CONFIG_SIFF_DEMUXER)              += siff.o

libavformat/rtp_vorbis.c

@@ -0,0 +1,218 @@
+/*
+ * RTP Vorbis Protocol (RFC5215)
+ * Copyright (c) 2009 Colin McQuillan
+ *
+ * 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
+ */
+
+/**
+ * @file libavformat/rtp_vorbis.c
+ * @brief Vorbis / RTP Code (RFC 5215)
+ * @author Colin McQuillan <m.niloc@gmail.com>
+ */
+
+#include "libavutil/base64.h"
+#include "libavutil/avstring.h"
+#include "libavcodec/bytestream.h"
+
+#include <assert.h>
+
+#include "rtpdec.h"
+#include "rtp_vorbis.h"
+
+/**
+ * RTP/Vorbis specific private data.
+ */
+struct PayloadContext {
+    unsigned ident;             ///< 24-bit stream configuration identifier
+};
+
+/**
+ * Length encoding described in RFC5215 section 3.1.1.
+ */
+static int get_base128(const uint8_t ** buf, const uint8_t * buf_end)
+{
+    int n = 0;
+    for (; *buf < buf_end; ++*buf) {
+        n <<= 7;
+        n += **buf & 0x7f;
+        if (!(**buf & 0x80)) {
+            ++*buf;
+            return n;
+        }
+    }
+    return 0;
+}
+
+/**
+ * Out-of-band headers, described in RFC 5251 section 3.2.1
+ */
+static unsigned int
+parse_packed_headers(const uint8_t * packed_headers,
+                     const uint8_t * packed_headers_end,
+                     AVCodecContext * codec, PayloadContext * vorbis_data)
+{
+    unsigned num_packed, num_headers, length, length1, length2;
+    uint8_t *ptr;
+
+    num_packed         = bytestream_get_be32(&packed_headers);
+    vorbis_data->ident = bytestream_get_be24(&packed_headers);
+    length             = bytestream_get_be16(&packed_headers);
+    num_headers        = get_base128(&packed_headers, packed_headers_end);
+    length1            = get_base128(&packed_headers, packed_headers_end);
+    length2            = get_base128(&packed_headers, packed_headers_end);
+
+    if (num_packed != 1 || num_headers > 3) {
+        av_log(codec, AV_LOG_ERROR,
+               "Unimplemented number of headers: %d packed headers, %d headers\n",
+               num_packed, num_headers);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (packed_headers_end - packed_headers != length ||
+        length1 > length || length2 > length - length1) {
+        av_log(codec, AV_LOG_ERROR,
+               "Bad packed header lengths (%d,%d,%d,%d)\n", length1,
+               length2, packed_headers_end - packed_headers, length);
+        return AVERROR_INVALIDDATA;
+    }
+
+    ptr = codec->extradata = av_mallocz(length + length / 255 + 64);
+    if (!ptr) {
+        av_log(codec, AV_LOG_ERROR, "Out of memory");
+        return AVERROR_NOMEM;
+    }
+    *ptr++ = 2;
+    ptr += av_xiphlacing(ptr, length1);
+    ptr += av_xiphlacing(ptr, length2);
+    memcpy(ptr, packed_headers, length);
+    ptr += length;
+    codec->extradata_size = ptr - codec->extradata;
+
+    return 0;
+}
+
+int
+ff_vorbis_parse_fmtp_config(AVCodecContext * codec,
+                            void *vorbis_data, char *attr, char *value)
+{
+    int result = 0;
+    assert(codec->codec_id == CODEC_ID_VORBIS);
+    assert(vorbis_data);
+
+    // The configuration value is a base64 encoded packed header
+    if (!strcmp(attr, "configuration")) {
+        uint8_t *decoded_packet = NULL;
+        int packet_size;
+        size_t decoded_alloc = strlen(value) / 4 * 3 + 4;
+
+        if (decoded_alloc <= INT_MAX) {
+            decoded_packet = av_malloc(decoded_alloc);
+            if (decoded_packet) {
+                packet_size =
+                    av_base64_decode(decoded_packet, value, decoded_alloc);
+
+                result = parse_packed_headers
+                    (decoded_packet, decoded_packet + packet_size, codec,
+                     vorbis_data);
+            } else {
+                av_log(codec, AV_LOG_ERROR,
+                       "Out of memory while decoding SDP configuration.\n");
+                result = AVERROR_NOMEM;
+            }
+        } else {
+            av_log(codec, AV_LOG_ERROR, "Packet too large\n");
+            result = AVERROR_INVALIDDATA;
+        }
+        av_free(decoded_packet);
+    }
+    return result;
+}
+
+static PayloadContext *vorbis_new_extradata(void)
+{
+    return av_mallocz(sizeof(PayloadContext));
+}
+
+static void vorbis_free_extradata(PayloadContext * data)
+{
+    av_free(data);
+}
+
+/**
+ * Handle payload as described in RFC 5215 section 2.2
+ */
+static int
+vorbis_handle_packet(AVFormatContext * ctx,
+                     PayloadContext * data,
+                     AVStream * st,
+                     AVPacket * pkt,
+                     uint32_t * timestamp,
+                     const uint8_t * buf, int len, int flags)
+{
+    int ident, fragmented, vdt, num_pkts, pkt_len;
+
+    if (len < 6) {
+        av_log(ctx, AV_LOG_ERROR, "Invalid %d byte packet\n", len);
+        return AVERROR_INVALIDDATA;
+    }
+
+    ident = AV_RB24(buf);
+    fragmented = buf[3] >> 6;
+    vdt = (buf[3] >> 4) & 3;
+    num_pkts = buf[3] & 7;
+    pkt_len = AV_RB16(buf + 4);
+
+    if (pkt_len > len - 6) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Invalid packet length %d in %d byte packet\n", pkt_len,
+               len);
+        return AVERROR_INVALIDDATA;
+    }
+
+    if (ident != data->ident) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Unimplemented Vorbis SDP configuration change detected\n");
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (fragmented != 0 || vdt != 0 || num_pkts != 1) {
+        av_log(ctx, AV_LOG_ERROR,
+               "Unimplemented RTP Vorbis packet settings (%d,%d,%d)\n",
+               fragmented, vdt, num_pkts);
+        return AVERROR_PATCHWELCOME;
+    }
+
+    if (av_new_packet(pkt, pkt_len)) {
+        av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
+        return AVERROR_NOMEM;
+    }
+
+    memcpy(pkt->data, buf + 6, pkt_len);
+    pkt->stream_index = st->index;
+    return 0;
+}
+
+RTPDynamicProtocolHandler ff_vorbis_dynamic_handler = {
+    "vorbis",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_VORBIS,
+    NULL,
+    vorbis_new_extradata,
+    vorbis_free_extradata,
+    vorbis_handle_packet
+};

libavformat/rtp_vorbis.h

@@ -0,0 +1,45 @@
+/*
+ * RTP Vorbis Protocol (RFC 5215)
+ * Copyright (c) 2009 Colin McQuillan
+ *
+ * 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 AVFORMAT_RTP_VORBIS_H
+#define AVFORMAT_RTP_VORBIS_H
+
+#include "libavcodec/avcodec.h"
+#include "rtpdec.h"
+
+/**
+ * Handle a Vorbis-specific FMTP parameter
+ *
+ * @param codec The context of the codec
+ * @param ctx Private Vorbis RTP context
+ * @param attr Format-specific parameter name
+ * @param value Format-specific paremeter value
+ */
+int
+ff_vorbis_parse_fmtp_config(AVCodecContext * codec,
+                            void *ctx, char *attr, char *value);
+
+/**
+ * Vorbis RTP callbacks.
+ */
+extern RTPDynamicProtocolHandler ff_vorbis_dynamic_handler;
+
+#endif /* AVFORMAT_RTP_VORBIS_H */

libavformat/rtpdec.c

@@ -32,6 +32,7 @@
 #include "rtpdec.h"
 #include "rtp_asf.h"
 #include "rtp_h264.h"
+#include "rtp_vorbis.h"
 
 //#define DEBUG
 
@@ -61,6 +62,7 @@ void av_register_rtp_dynamic_payload_handlers(void)
     ff_register_dynamic_payload_handler(&mp4v_es_handler);
     ff_register_dynamic_payload_handler(&mpeg4_generic_handler);
     ff_register_dynamic_payload_handler(&ff_h264_dynamic_handler);
+    ff_register_dynamic_payload_handler(&ff_vorbis_dynamic_handler);
 
     ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfv_handler);
     ff_register_dynamic_payload_handler(&ff_ms_rtp_asf_pfa_handler);

libavformat/rtsp.c

@@ -37,6 +37,7 @@
 #include "rtpdec.h"
 #include "rdt.h"
 #include "rtp_asf.h"
+#include "rtp_vorbis.h"
 
 //#define DEBUG
 //#define DEBUG_RTP_TCP
@@ -196,7 +197,8 @@ static int hex_to_data(uint8_t *data, const char *p)
     return len;
 }
 
-static void sdp_parse_fmtp_config(AVCodecContext *codec, char *attr, char *value)
+static void sdp_parse_fmtp_config(AVCodecContext * codec, void *ctx,
+                                  char *attr, char *value)
 {
     switch (codec->codec_id) {
         case CODEC_ID_MPEG4:
@@ -213,6 +215,9 @@ static void sdp_parse_fmtp_config(AVCodecContext *codec, char *attr, char *value
                 hex_to_data(codec->extradata, value);
             }
             break;
+        case CODEC_ID_VORBIS:
+            ff_vorbis_parse_fmtp_config(codec, ctx, attr, value);
+            break;
         default:
             break;
     }
@@ -274,7 +279,8 @@ static void sdp_parse_fmtp(AVStream *st, const char *p)
     while(rtsp_next_attr_and_value(&p, attr, sizeof(attr), value, sizeof(value)))
     {
         /* grab the codec extra_data from the config parameter of the fmtp line */
-        sdp_parse_fmtp_config(codec, attr, value);
+        sdp_parse_fmtp_config(codec, rtsp_st->dynamic_protocol_context,
+                              attr, value);
         /* Looking for a known attribute */
         for (i = 0; attr_names[i].str; ++i) {
             if (!strcasecmp(attr, attr_names[i].str)) {