[FFmpeg-devel] [PATCH 3/3] avformat/rtpdec_ac3: add AC3 RTP depacketization (RFC 4184)
Gilles Chanteperdrix
gilles.chanteperdrix at xenomai.org
Fri Feb 13 22:51:34 CET 2015
Signed-off-by: Gilles Chanteperdrix <gilles.chanteperdrix at xenomai.org>
---
Changelog | 1 +
MAINTAINERS | 1 +
libavformat/Makefile | 1 +
libavformat/rtpdec.c | 1 +
libavformat/rtpdec_ac3.c | 157 +++++++++++++++++++++++++++++++++++++++++++
libavformat/rtpdec_formats.h | 1 +
libavformat/version.h | 4 +-
7 files changed, 164 insertions(+), 2 deletions(-)
create mode 100644 libavformat/rtpdec_ac3.c
diff --git a/Changelog b/Changelog
index 775fc79..085fd17 100644
--- a/Changelog
+++ b/Changelog
@@ -24,6 +24,7 @@ version <next>:
- ported softpulldown filter from libmpcodecs as repeatfields filter
- dcshift filter
- RTP parser for loss tolerant payload format for MP3 audio (RFC 5219)
+- RTP parser for AC3 payload format (RFC 4184)
version 2.5:
diff --git a/MAINTAINERS b/MAINTAINERS
index 13b211e..8430222 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -465,6 +465,7 @@ Muxers/Demuxers:
rmdec.c, rmenc.c Ronald S. Bultje, Kostya Shishkov
rtmp* Kostya Shishkov
rtp.c, rtpenc.c Martin Storsjo
+ rtpdec_ac3.* Gilles Chanteperdrix
rtpdec_h261.*, rtpenc_h261.* Thomas Volkert
rtpdec_hevc.*, rtpenc_hevc.* Thomas Volkert
rtpdec_asf.* Ronald S. Bultje
diff --git a/libavformat/Makefile b/libavformat/Makefile
index ec312ba..073a42d 100644
--- a/libavformat/Makefile
+++ b/libavformat/Makefile
@@ -29,6 +29,7 @@ OBJS-$(CONFIG_RIFFENC) += riffenc.o
OBJS-$(CONFIG_RTPDEC) += rdt.o \
rtp.o \
rtpdec.o \
+ rtpdec_ac3.o \
rtpdec_amr.o \
rtpdec_asf.o \
rtpdec_g726.o \
diff --git a/libavformat/rtpdec.c b/libavformat/rtpdec.c
index c632340..550da4a 100644
--- a/libavformat/rtpdec.c
+++ b/libavformat/rtpdec.c
@@ -72,6 +72,7 @@ void ff_register_dynamic_payload_handler(RTPDynamicProtocolHandler *handler)
void ff_register_rtp_dynamic_payload_handlers(void)
{
+ ff_register_dynamic_payload_handler(&ff_ac3_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_amr_nb_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_amr_wb_dynamic_handler);
ff_register_dynamic_payload_handler(&ff_g726_16_dynamic_handler);
diff --git a/libavformat/rtpdec_ac3.c b/libavformat/rtpdec_ac3.c
new file mode 100644
index 0000000..728f421
--- /dev/null
+++ b/libavformat/rtpdec_ac3.c
@@ -0,0 +1,157 @@
+/*
+ * RTP parser for AC3 payload format (RFC 4184)
+ * Copyright (c) 2015 Gilles Chanteperdrix <gch at xenomai.org>
+ *
+ * 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
+ */
+
+#include "avformat.h"
+#include "rtpdec_formats.h"
+
+#define RTP_AC3_PAYLOAD_HEADER_SIZE 2
+
+struct PayloadContext {
+ unsigned nr_frames;
+ unsigned last_frame;
+ uint32_t timestamp;
+ AVIOContext *fragment;
+};
+
+static av_cold int ac3_init(AVFormatContext *s, int st_index,
+ PayloadContext *data)
+{
+ if (st_index < 0)
+ return 0;
+ s->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
+ return 0;
+}
+
+static PayloadContext *ac3_new_context(void)
+{
+ return av_mallocz(sizeof(PayloadContext));
+}
+
+static inline void free_fragment_if_needed(PayloadContext *data)
+{
+ if (data->fragment) {
+ uint8_t *p;
+ avio_close_dyn_buf(data->fragment, &p);
+ av_free(p);
+ data->fragment = NULL;
+ }
+}
+
+static void ac3_free_context(PayloadContext *data)
+{
+ free_fragment_if_needed(data);
+ av_free(data);
+}
+
+static int ac3_handle_packet(AVFormatContext *ctx, PayloadContext *data,
+ AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+ const uint8_t *buf, int len, uint16_t seq,
+ int flags)
+{
+ unsigned frame_type;
+ unsigned nr_frames;
+ int err;
+
+ if (len < RTP_AC3_PAYLOAD_HEADER_SIZE + 1) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid %d bytes packet\n", len);
+ return AVERROR_INVALIDDATA;
+ }
+
+ frame_type = buf[0] & 0x3;
+ nr_frames = buf[1];
+ buf += RTP_AC3_PAYLOAD_HEADER_SIZE;
+ len -= RTP_AC3_PAYLOAD_HEADER_SIZE;
+
+ switch (frame_type) {
+ case 0: /* One or more complete frames */
+ if (!nr_frames) {
+ av_log(ctx, AV_LOG_ERROR, "Invalid AC3 packet data\n");
+ return AVERROR_INVALIDDATA;
+ }
+ if (av_new_packet(pkt, len)) {
+ av_log(ctx, AV_LOG_ERROR, "Out of memory.\n");
+ return AVERROR(ENOMEM);
+ }
+
+ pkt->stream_index = st->index;
+ memcpy(pkt->data, buf, len);
+ return 0;
+
+ case 1:
+ case 2: /* First fragment */
+ free_fragment_if_needed(data);
+
+ data->last_frame = 1;
+ data->nr_frames = nr_frames;
+ err = avio_open_dyn_buf(&data->fragment);
+ if (err < 0)
+ return err;
+
+ avio_write(data->fragment, buf, len);
+ data->timestamp = *timestamp;
+ return AVERROR(EAGAIN);
+
+ case 3: /* Fragment other than first */
+ if (!data->fragment) {
+ av_log(ctx, AV_LOG_WARNING,
+ "Received packet without a start fragment; dropping.\n");
+ return AVERROR(EAGAIN);
+ }
+ if (nr_frames != data->nr_frames ||
+ data->timestamp != *timestamp) {
+ free_fragment_if_needed(data);
+ av_log(ctx, AV_LOG_ERROR, "Invalid packet received\n");
+ return AVERROR_INVALIDDATA;
+ }
+
+ avio_write(data->fragment, buf, len);
+ data->last_frame++;
+ }
+
+ if (!(flags & RTP_FLAG_MARKER))
+ return AVERROR(EAGAIN);
+
+ if (data->last_frame != data->nr_frames) {
+ free_fragment_if_needed(data);
+ av_log(ctx, AV_LOG_ERROR, "Missed %d packets\n",
+ data->nr_frames - data->last_frame);
+ return AVERROR_INVALIDDATA;
+ }
+
+ err = ff_rtp_finalize_packet(pkt, &data->fragment, st->index);
+ if (err < 0) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Error occurred when getting fragment buffer.");
+ return err;
+ }
+
+ return 0;
+}
+
+RTPDynamicProtocolHandler ff_ac3_dynamic_handler = {
+ .enc_name = "ac3",
+ .codec_type = AVMEDIA_TYPE_AUDIO,
+ .codec_id = AV_CODEC_ID_AC3,
+ .init = ac3_init,
+ .alloc = ac3_new_context,
+ .free = ac3_free_context,
+ .parse_packet = ac3_handle_packet,
+};
diff --git a/libavformat/rtpdec_formats.h b/libavformat/rtpdec_formats.h
index da22d70..b38cf1b 100644
--- a/libavformat/rtpdec_formats.h
+++ b/libavformat/rtpdec_formats.h
@@ -35,6 +35,7 @@ int ff_h263_handle_packet(AVFormatContext *ctx, PayloadContext *data,
AVStream *st, AVPacket *pkt, uint32_t *timestamp,
const uint8_t *buf, int len, uint16_t seq, int flags);
+extern RTPDynamicProtocolHandler ff_ac3_dynamic_handler;
extern RTPDynamicProtocolHandler ff_amr_nb_dynamic_handler;
extern RTPDynamicProtocolHandler ff_amr_wb_dynamic_handler;
extern RTPDynamicProtocolHandler ff_g726_16_dynamic_handler;
diff --git a/libavformat/version.h b/libavformat/version.h
index 84749ec..f7fe97e 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -30,8 +30,8 @@
#include "libavutil/version.h"
#define LIBAVFORMAT_VERSION_MAJOR 56
-#define LIBAVFORMAT_VERSION_MINOR 20
-#define LIBAVFORMAT_VERSION_MICRO 102
+#define LIBAVFORMAT_VERSION_MINOR 21
+#define LIBAVFORMAT_VERSION_MICRO 103
#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
LIBAVFORMAT_VERSION_MINOR, \
--
1.8.4
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