rtpdec: DV depacketizer (RFC 6469)

(tested with live555 RTSP server)

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

1 files changed, 169 insertions, 0 deletions

diff --git a/libavformat/rtpdec_dv.c b/libavformat/rtpdec_dv.c
new file mode 100644
index 0000000000..f64b06fcfc
--- /dev/null
+++ b/libavformat/rtpdec_dv.c
@@ -0,0 +1,169 @@
+/*
+ * RTP parser for DV payload format (RFC 6469)
+ * Copyright (c) 2015 Thomas Volkert <thomas@homer-conferencing.com>
+ *
+ * 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 "libavutil/avstring.h"
+
+#include "libavcodec/bytestream.h"
+
+#include "rtpdec_formats.h"
+
+struct PayloadContext {
+    AVIOContext *buf;
+    uint32_t    timestamp;
+    int         bundled_audio;
+};
+
+static av_cold PayloadContext *dv_new_context(void)
+{
+    return av_mallocz(sizeof(PayloadContext));
+}
+
+static void dv_free_dyn_buffer(AVIOContext **dyn_buf)
+{
+    uint8_t *ptr_dyn_buffer;
+    avio_close_dyn_buf(*dyn_buf, &ptr_dyn_buffer);
+    av_free(ptr_dyn_buffer);
+    *dyn_buf = NULL;
+}
+
+static av_cold void dv_free_context(PayloadContext *data)
+{
+    dv_free_dyn_buffer(&data->buf);
+    av_free(data);
+}
+
+static av_cold int dv_init(AVFormatContext *ctx, int st_index,
+                           PayloadContext *data)
+{
+    av_dlog(ctx, "dv_init() for stream %d\n", st_index);
+
+    if (st_index < 0)
+        return 0;
+
+    ctx->streams[st_index]->need_parsing = AVSTREAM_PARSE_FULL;
+
+    return 0;
+}
+
+static av_cold int dv_sdp_parse_fmtp_config(AVFormatContext *s,
+                                            AVStream *stream,
+                                            PayloadContext *dv_data,
+                                            char *attr, char *value)
+{
+    /* does the DV stream include audio? */
+    if (!strcmp(attr, "audio") && !strcmp(value, "bundled"))
+        dv_data->bundled_audio = 1;
+
+    /* extract the DV profile */
+    if (!strcmp(attr, "encode")) {
+        /* SD-VCR/525-60 */
+        /* SD-VCR/625-50 */
+        /* HD-VCR/1125-60 */
+        /* HD-VCR/1250-50 */
+        /* SDL-VCR/525-60 */
+        /* SDL-VCR/625-50 */
+        /* 314M-25/525-60 */
+        /* 314M-25/625-50 */
+        /* 314M-50/525-60 */
+        /* 314M-50/625-50 */
+        /* 370M/1080-60i */
+        /* 370M/1080-50i */
+        /* 370M/720-60p */
+        /* 370M/720-50p */
+        /* 306M/525-60 (for backward compatibility) */
+        /* 306M/625-50 (for backward compatibility) */
+    }
+
+    return 0;
+}
+
+static av_cold int dv_parse_sdp_line(AVFormatContext *ctx, int st_index,
+                                     PayloadContext *dv_data, const char *line)
+{
+    AVStream *current_stream;
+    const char *sdp_line_ptr = line;
+
+    if (st_index < 0)
+        return 0;
+
+    current_stream = ctx->streams[st_index];
+
+    if (av_strstart(sdp_line_ptr, "fmtp:", &sdp_line_ptr)) {
+        return ff_parse_fmtp(ctx, current_stream, dv_data, sdp_line_ptr,
+                             dv_sdp_parse_fmtp_config);
+    }
+
+    return 0;
+}
+
+static int dv_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_dv_ctx,
+                            AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                            const uint8_t *buf, int len, uint16_t seq,
+                            int flags)
+{
+    int res = 0;
+
+    /* drop data of previous packets in case of non-continuous (lossy) packet stream */
+    if (rtp_dv_ctx->buf && rtp_dv_ctx->timestamp != *timestamp) {
+        dv_free_dyn_buffer(&rtp_dv_ctx->buf);
+    }
+
+    /* sanity check for size of input packet: 1 byte payload at least */
+    if (len < 1) {
+        av_log(ctx, AV_LOG_ERROR, "Too short RTP/DV packet, got %d bytes\n", len);
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* start frame buffering with new dynamic buffer */
+    if (!rtp_dv_ctx->buf) {
+        res = avio_open_dyn_buf(&rtp_dv_ctx->buf);
+        if (res < 0)
+            return res;
+        /* update the timestamp in the frame packet with the one from the RTP packet */
+        rtp_dv_ctx->timestamp = *timestamp;
+    }
+
+    /* write the fragment to the dyn. buffer */
+    avio_write(rtp_dv_ctx->buf, buf, len);
+
+    /* RTP marker bit means: last fragment of current frame was received;
+       otherwise, an additional fragment is needed for the current frame */
+    if (!(flags & RTP_FLAG_MARKER))
+        return AVERROR(EAGAIN);
+
+    /* close frame buffering and create resulting A/V packet */
+    res = ff_rtp_finalize_packet(pkt, &rtp_dv_ctx->buf, st->index);
+    if (res < 0)
+        return res;
+
+    return 0;
+}
+
+RTPDynamicProtocolHandler ff_dv_dynamic_handler = {
+    .enc_name         = "DV",
+    .codec_type       = AVMEDIA_TYPE_VIDEO,
+    .codec_id         = AV_CODEC_ID_DVVIDEO,
+    .init             = dv_init,
+    .parse_sdp_a_line = dv_parse_sdp_line,
+    .alloc            = dv_new_context,
+    .free             = dv_free_context,
+    .parse_packet     = dv_handle_packet
+};