[vlc-devel] [PATCH] rtp: JPEG packetization

Samuel Pitoiset samuel.pitoiset at gmail.com
Wed Aug 29 23:08:00 CEST 2012


---
 modules/stream_out/rtpfmt.c | 50 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 49 insertions(+), 1 deletion(-)

diff --git a/modules/stream_out/rtpfmt.c b/modules/stream_out/rtpfmt.c
index 79ae441..5a6e726 100644
--- a/modules/stream_out/rtpfmt.c
+++ b/modules/stream_out/rtpfmt.c
@@ -53,6 +53,7 @@ static int rtp_packetize_g726_24 (sout_stream_id_t *, block_t *);
 static int rtp_packetize_g726_32 (sout_stream_id_t *, block_t *);
 static int rtp_packetize_g726_40 (sout_stream_id_t *, block_t *);
 static int rtp_packetize_xiph (sout_stream_id_t *, block_t *);
+static int rtp_packetize_jpeg (sout_stream_id_t *, block_t *);
 
 #define XIPH_IDENT (0)
 
@@ -511,7 +512,11 @@ int rtp_get_fmt( vlc_object_t *obj, es_format_t *p_fmt, const char *mux,
             rtp_fmt->clock_rate = 1000;
             rtp_fmt->pf_packetize = rtp_packetize_t140;
             break;
-
+        case VLC_CODEC_MJPG:
+            rtp_fmt->payload_type = 26;
+            rtp_fmt->ptname = "JPEG";
+            rtp_fmt->pf_packetize = rtp_packetize_jpeg;
+            break;
         default:
             msg_Err( obj, "cannot add this stream (unsupported "
                      "codec: %4.4s)", (char*)&p_fmt->i_codec );
@@ -660,6 +665,49 @@ static int rtp_packetize_xiph( sout_stream_id_t *id, block_t *in )
     return VLC_SUCCESS;
 }
 
+/* rfc2435 */
+/* TODO: Do not hardcoded video pixel dimensions */
+#define DEFAULT_JPEG_WIDTH  39 /* 312px */
+#define DEFAULT_JPEG_HEIGHT 29 /* 232px */
+static int rtp_packetize_jpeg( sout_stream_id_t *id, block_t *in )
+{
+    int      i_max   = rtp_mtu (id) - 8; /* payload max in one packet */
+    int      i_count = ( in->i_buffer + i_max - 1 ) / i_max;
+
+    uint8_t  *p_data = in->p_buffer;
+    int      i_data  = in->i_buffer;
+    uint32_t i_off   = 0; /* fragment offset of the current JPEG frame */
+
+    for( int i = 0; i < i_count; i++ )
+    {
+        int i_payload = __MIN( i_max, i_data );
+        block_t *out  = block_Alloc( 20 + i_payload );
+
+        /* Type-specific:8, Fragment Offset:24, Type:8, Q:8, Width:8, Height:8 */
+        uint64_t header = ((uint64_t)0 << 56) | ((uint64_t)i_off << 32) |
+                          (0 << 24) | (0 << 16) | (DEFAULT_JPEG_WIDTH << 8) |
+                          DEFAULT_JPEG_HEIGHT;
+
+        /* rtp common header */
+        rtp_packetize_common( id, out, (i == i_count - 1) ? 1 : 0, in->i_dts );
+
+        SetQWBE( out->p_buffer + 12, header );
+        memcpy( &out->p_buffer[20], p_data, i_payload );
+
+        out->i_buffer = 20 + i_payload;
+        out->i_dts    = in->i_dts + i * in->i_length / i_count;
+        out->i_length = in->i_length / i_count;
+
+        rtp_packetize_send( id, out );
+
+        p_data += i_payload;
+        i_data -= i_payload;
+        i_off  += i_payload;
+    }
+
+    return VLC_SUCCESS;
+}
+
 static int rtp_packetize_mpa( sout_stream_id_t *id, block_t *in )
 {
     int     i_max   = rtp_mtu (id) - 4; /* payload max in one packet */
-- 
1.7.11.3




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