[FFmpeg-devel] [PATCH 3/3] avformat/rtpdec_ac3: add AC3 RTP depacketization (RFC 4184)

Michael Niedermayer michaelni at gmx.at
Sat Feb 14 20:20:01 CET 2015


On Sat, Feb 14, 2015 at 07:21:04PM +0100, Thomas Volkert wrote:
> On 02/13/2015 10:51 PM, Gilles Chanteperdrix wrote:
> >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, \
> 
> Okay.

applied

thanks

[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Frequently ignored answer#1 FFmpeg bugs should be sent to our bugtracker. User
questions about the command line tools should be sent to the ffmpeg-user ML.
And questions about how to use libav* should be sent to the libav-user ML.
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