Merge commit 'a505c0d7373336a4cc5aa2022111c46bdd388b1f'

* commit 'a505c0d7373336a4cc5aa2022111c46bdd388b1f':
  rtp: Initial H.261 support

Conflicts:
	Changelog
	libavformat/rtpdec_h261.c
	libavformat/rtpenc_h261.c
	libavformat/sdp.c
	libavformat/version.h

See: 50a4d5cfc6749932347ee38c25b5040aea4b13a0
Merged-by: Michael Niedermayer <michaelni@gmx.at>

7 files changed, 138 insertions, 86 deletions

diff --git a/Changelog b/Changelog
index 59a26c2..517145d 100644
--- a/Changelog
+++ b/Changelog
@@ -34,7 +34,7 @@ version 2.4:
 - ICY metadata are now requested by default with the HTTP protocol
 - support for using metadata in stream specifiers in fftools
 - LZMA compression support in TIFF decoder
-- support for H.261 RTP payload format (RFC 4587)
+- H.261 RTP payload format (RFC 4587) depacketizer and experimental packetizer
 - HEVC/H.265 RTP payload format (draft v6) depacketizer
 - added codecview filter to visualize information exported by some codecs
 - Matroska 3D support thorugh side data
diff --git a/libavformat/rtpdec_formats.h b/libavformat/rtpdec_formats.h
index 803410e..87e316f 100644
--- a/libavformat/rtpdec_formats.h
+++ b/libavformat/rtpdec_formats.h
@@ -31,10 +31,6 @@
  */
 int ff_wms_parse_sdp_a_line(AVFormatContext *s, const char *p);
 
-int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
-                          AVStream *st, AVPacket *pkt, uint32_t *timestamp,
-                          const uint8_t *buf, int len, uint16_t seq, int flags);
-
 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);
diff --git a/libavformat/rtpdec_h261.c b/libavformat/rtpdec_h261.c
index 43244bb..9f34889 100644
--- a/libavformat/rtpdec_h261.c
+++ b/libavformat/rtpdec_h261.c
@@ -19,11 +19,11 @@
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
+#include "libavcodec/get_bits.h"
 #include "avformat.h"
 #include "rtpdec_formats.h"
-#include "libavcodec/get_bits.h"
 
-#define RTP_H261_PAYLOAD_HEADER_SIZE                    4
+#define RTP_H261_PAYLOAD_HEADER_SIZE 4
 
 struct PayloadContext {
     AVIOContext *buf;
@@ -63,8 +63,6 @@ static av_cold void h261_free_context(PayloadContext *pl_ctx)
 static av_cold int h261_init(AVFormatContext *ctx, int st_index,
                              PayloadContext *data)
 {
-    //av_log(ctx, AV_LOG_DEBUG, "h261_init() for stream %d\n", st_index);
-
     if (st_index < 0)
         return 0;
 
@@ -73,16 +71,18 @@ static av_cold int h261_init(AVFormatContext *ctx, int st_index,
     return 0;
 }
 
-int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
-                          AVStream *st, AVPacket *pkt, uint32_t *timestamp,
-                          const uint8_t *buf, int len, uint16_t seq, int flags)
+static int h261_handle_packet(AVFormatContext *ctx, PayloadContext *rtp_h261_ctx,
+                              AVStream *st, AVPacket *pkt, uint32_t *timestamp,
+                              const uint8_t *buf, int len, uint16_t seq,
+                              int flags)
 {
     int sbit, ebit, gobn, mbap, quant;
     int res;
 
-    /* drop data of previous packets in case of non-continuous (loss) packet stream */
-    if (data->buf && data->timestamp != *timestamp) {
-        h261_free_dyn_buffer(&data->buf);
+    /* drop data of previous packets in case of non-continuous (lossy) packet stream */
+    if (rtp_h261_ctx->buf && rtp_h261_ctx->timestamp != *timestamp) {
+        h261_free_dyn_buffer(&rtp_h261_ctx->buf);
+        rtp_h261_ctx->endbyte_bits = 0;
     }
 
     /* sanity check for size of input packet: 1 byte payload at least */
@@ -92,26 +92,25 @@ int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
     }
 
     /*
-      decode the H.261 payload header according to section 4.1 of RFC 4587:
-      (uses 4 bytes between RTP header and H.261 stream per packet)
-
-         0                   1                   2                   3
-         0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
-        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-        |SBIT |EBIT |I|V| GOBN  |   MBAP  |  QUANT  |  HMVD   |  VMVD   |
-        +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
-
-           Start bit position (SBIT): 3 bits
-           End bit position (EBIT): 3 bits
-           INTRA-frame encoded data (I): 1 bit
-           Motion Vector flag (V): 1 bit
-           GOB number (GOBN): 4 bits
-           Macroblock address predictor (MBAP): 5 bits
-           Quantizer (QUANT): 5 bits
-           Horizontal motion vector data (HMVD): 5 bits
-           Vertical motion vector data (VMVD): 5 bits
-
-    */
+     * decode the H.261 payload header according to section 4.1 of RFC 4587:
+     * (uses 4 bytes between RTP header and H.261 stream per packet)
+     *
+     *    0                   1                   2                   3
+     *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+     *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     *   |SBIT |EBIT |I|V| GOBN  |   MBAP  |  QUANT  |  HMVD   |  VMVD   |
+     *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+     *
+     *      Start bit position (SBIT): 3 bits
+     *      End bit position (EBIT): 3 bits
+     *      INTRA-frame encoded data (I): 1 bit
+     *      Motion Vector flag (V): 1 bit
+     *      GOB number (GOBN): 4 bits
+     *      Macroblock address predictor (MBAP): 5 bits
+     *      Quantizer (QUANT): 5 bits
+     *      Horizontal motion vector data (HMVD): 5 bits
+     *      Vertical motion vector data (VMVD): 5 bits
+     */
     sbit  =  (buf[0] >> 5) & 0x07;
     ebit  =  (buf[0] >> 2) & 0x07;
     gobn  =  (buf[1] >> 4) & 0x0f;
@@ -123,14 +122,14 @@ int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
     len -= RTP_H261_PAYLOAD_HEADER_SIZE;
 
     /* start frame buffering with new dynamic buffer */
-    if (!data->buf) {
-        /* sanity check: a new frame starts with gobn=0, sbit=0, mbap=0, uqnat=0 */
-        if (!gobn  && !sbit && !mbap && !quant){
-            res = avio_open_dyn_buf(&data->buf);
+    if (!rtp_h261_ctx->buf) {
+        /* sanity check: a new frame starts with gobn=0, sbit=0, mbap=0, quant=0 */
+        if (!gobn && !sbit && !mbap && !quant) {
+            res = avio_open_dyn_buf(&rtp_h261_ctx->buf);
             if (res < 0)
                 return res;
             /* update the timestamp in the frame packet with the one from the RTP packet */
-            data->timestamp = *timestamp;
+            rtp_h261_ctx->timestamp = *timestamp;
         } else {
             /* frame not started yet, need more packets */
             return AVERROR(EAGAIN);
@@ -138,39 +137,39 @@ int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
     }
 
     /* do the "byte merging" at the boundaries of two consecutive frame fragments */
-    if (data->endbyte_bits || sbit) {
-        if (data->endbyte_bits == sbit) {
-            data->endbyte |= buf[0] & (0xff >> sbit);
-            data->endbyte_bits = 0;
+    if (rtp_h261_ctx->endbyte_bits || sbit) {
+        if (rtp_h261_ctx->endbyte_bits == sbit) {
+            rtp_h261_ctx->endbyte     |= buf[0] & (0xff >> sbit);
+            rtp_h261_ctx->endbyte_bits = 0;
             buf++;
             len--;
-            avio_w8(data->buf, data->endbyte);
+            avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
         } else {
             /* ebit/sbit values inconsistent, assuming packet loss */
             GetBitContext gb;
             init_get_bits(&gb, buf, len*8 - ebit);
             skip_bits(&gb, sbit);
-            if (data->endbyte_bits) {
-                data->endbyte |= get_bits(&gb, 8 - data->endbyte_bits);
-                avio_w8(data->buf, data->endbyte);
+            if (rtp_h261_ctx->endbyte_bits) {
+                rtp_h261_ctx->endbyte |= get_bits(&gb, 8 - rtp_h261_ctx->endbyte_bits);
+                avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
             }
             while (get_bits_left(&gb) >= 8)
-                avio_w8(data->buf, get_bits(&gb, 8));
-            data->endbyte_bits = get_bits_left(&gb);
-            if (data->endbyte_bits)
-                data->endbyte = get_bits(&gb, data->endbyte_bits) <<
-                                (8 - data->endbyte_bits);
+                avio_w8(rtp_h261_ctx->buf, get_bits(&gb, 8));
+            rtp_h261_ctx->endbyte_bits = get_bits_left(&gb);
+            if (rtp_h261_ctx->endbyte_bits)
+                rtp_h261_ctx->endbyte = get_bits(&gb, rtp_h261_ctx->endbyte_bits) <<
+                                        (8 - rtp_h261_ctx->endbyte_bits);
             ebit = 0;
-            len = 0;
+            len  = 0;
         }
     }
     if (ebit) {
         if (len > 0)
-            avio_write(data->buf, buf, len - 1);
-        data->endbyte_bits = 8 - ebit;
-        data->endbyte = buf[len - 1] & (0xff << ebit);
+            avio_write(rtp_h261_ctx->buf, buf, len - 1);
+        rtp_h261_ctx->endbyte_bits = 8 - ebit;
+        rtp_h261_ctx->endbyte      = buf[len - 1] & (0xff << ebit);
     } else {
-        avio_write(data->buf, buf, len);
+        avio_write(rtp_h261_ctx->buf, buf, len);
     }
 
     /* RTP marker bit means: last fragment of current frame was received;
@@ -179,12 +178,12 @@ int ff_h261_handle_packet(AVFormatContext *ctx, PayloadContext *data,
         return AVERROR(EAGAIN);
 
     /* write the completed last byte from the "byte merging" */
-    if (data->endbyte_bits)
-        avio_w8(data->buf, data->endbyte);
-    data->endbyte_bits = 0;
+    if (rtp_h261_ctx->endbyte_bits)
+        avio_w8(rtp_h261_ctx->buf, rtp_h261_ctx->endbyte);
+    rtp_h261_ctx->endbyte_bits = 0;
 
     /* close frame buffering and create resulting A/V packet */
-    res = ff_rtp_finalize_packet(pkt, &data->buf, st->index);
+    res = ff_rtp_finalize_packet(pkt, &rtp_h261_ctx->buf, st->index);
     if (res < 0)
         return res;
 
@@ -196,8 +195,8 @@ RTPDynamicProtocolHandler ff_h261_dynamic_handler = {
     .codec_type        = AVMEDIA_TYPE_VIDEO,
     .codec_id          = AV_CODEC_ID_H261,
     .init              = h261_init,
-    .parse_packet      = ff_h261_handle_packet,
     .alloc             = h261_new_context,
     .free              = h261_free_context,
+    .parse_packet      = h261_handle_packet,
     .static_payload_id = 31,
 };
diff --git a/libavformat/rtpenc.c b/libavformat/rtpenc.c
index ef8b33c..c4c4d3e 100644
--- a/libavformat/rtpenc.c
+++ b/libavformat/rtpenc.c
@@ -89,7 +89,7 @@ static int is_supported(enum AVCodecID id)
 static int rtp_write_header(AVFormatContext *s1)
 {
     RTPMuxContext *s = s1->priv_data;
-    int n;
+    int n, ret = AVERROR(EINVAL);
     AVStream *st;
 
     if (s1->nb_streams != 1) {
@@ -195,6 +195,17 @@ static int rtp_write_header(AVFormatContext *s1)
         s->max_payload_size = n * TS_PACKET_SIZE;
         s->buf_ptr = s->buf;
         break;
+    case AV_CODEC_ID_H261:
+        if (s1->strict_std_compliance > FF_COMPLIANCE_EXPERIMENTAL) {
+            av_log(s, AV_LOG_ERROR,
+                   "Packetizing H261 is experimental and produces incorrect "
+                   "packetization for cases where GOBs don't fit into packets "
+                   "(even though most receivers may handle it just fine). "
+                   "Please set -f_strict experimental in order to enable it.\n");
+            ret = AVERROR_EXPERIMENTAL;
+            goto fail;
+        }
+        break;
     case AV_CODEC_ID_H264:
         /* check for H.264 MP4 syntax */
         if (st->codec->extradata_size > 4 && st->codec->extradata[0] == 1) {
@@ -277,7 +288,7 @@ defaultcase:
 
 fail:
     av_freep(&s->buf);
-    return AVERROR(EINVAL);
+    return ret;
 }
 
 /* send an rtcp sender report packet */
diff --git a/libavformat/rtpenc_h261.c b/libavformat/rtpenc_h261.c
index 6f63703..9930b71 100644
--- a/libavformat/rtpenc_h261.c
+++ b/libavformat/rtpenc_h261.c
@@ -22,36 +22,81 @@
 #include "avformat.h"
 #include "rtpenc.h"
 
-void ff_rtp_send_h261(AVFormatContext *s1, const uint8_t *frame_buf, int frame_size)
+#define RTP_H261_HEADER_SIZE 4
+
+static const uint8_t *find_resync_marker_reverse(const uint8_t *restrict start,
+                                                 const uint8_t *restrict end)
+{
+    const uint8_t *p = end - 1;
+    start += 1; /* Make sure we never return the original start. */
+    for (; p > start; p--) {
+        if (p[0] == 0 && p[1] == 1)
+            return p;
+    }
+    return end;
+}
+
+void ff_rtp_send_h261(AVFormatContext *ctx, const uint8_t *frame_buf, int frame_size)
 {
-    RTPMuxContext *rtp_ctx = s1->priv_data;
-    int processed_frame_size;
+    int cur_frame_size;
     int last_packet_of_frame;
-    uint8_t *tmp_buf_ptr;
+    RTPMuxContext *rtp_ctx = ctx->priv_data;
 
     /* use the default 90 KHz time stamp */
     rtp_ctx->timestamp = rtp_ctx->cur_timestamp;
 
     /* continue as long as not all frame data is processed */
     while (frame_size > 0) {
-        tmp_buf_ptr = rtp_ctx->buf;
-        *tmp_buf_ptr++ = 1; /* V=1 */
-        *tmp_buf_ptr++ = 0;
-        *tmp_buf_ptr++ = 0;
-        *tmp_buf_ptr++ = 0;
-
-        processed_frame_size = FFMIN(rtp_ctx->max_payload_size - 4, frame_size);
+        /*
+         * encode the H.261 payload header according to section 4.1 of RFC 4587:
+         * (uses 4 bytes between RTP header and H.261 stream per packet)
+         *
+         *    0                   1                   2                   3
+         *    0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+         *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+         *   |SBIT |EBIT |I|V| GOBN  |   MBAP  |  QUANT  |  HMVD   |  VMVD   |
+         *   +-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
+         *
+         *      Start bit position (SBIT): 3 bits
+         *      End bit position (EBIT): 3 bits
+         *      INTRA-frame encoded data (I): 1 bit
+         *      Motion Vector flag (V): 1 bit
+         *      GOB number (GOBN): 4 bits
+         *      Macroblock address predictor (MBAP): 5 bits
+         *      Quantizer (QUANT): 5 bits
+         *      Horizontal motion vector data (HMVD): 5 bits
+         *      Vertical motion vector data (VMVD): 5 bits
+         */
+        rtp_ctx->buf[0] = 1; /* sbit=0, ebit=0, i=0, v=1 */
+        rtp_ctx->buf[1] = 0; /* gobn=0, mbap=0 */
+        rtp_ctx->buf[2] = 0; /* quant=0, hmvd=5 */
+        rtp_ctx->buf[3] = 0; /* vmvd=0 */
+        if (frame_size < 2 || frame_buf[0] != 0 || frame_buf[1] != 1) {
+            /* A full, correct fix for this would be to make the H261 encoder
+             * support inserting extra GOB headers (triggered by setting e.g.
+             * "-ps 1"), and including information about macroblock boundaries
+             * (such as for h263_rfc2190). */
+            av_log(ctx, AV_LOG_WARNING,
+                   "RTP/H261 packet not cut at a GOB boundary, not signaled correctly\n");
+        }
 
-        //XXX: parse the h.261 bitstream and improve frame splitting here
+        cur_frame_size = FFMIN(rtp_ctx->max_payload_size - RTP_H261_HEADER_SIZE, frame_size);
 
-        last_packet_of_frame = (processed_frame_size == frame_size);
+        /* look for a better place to split the frame into packets */
+        if (cur_frame_size < frame_size) {
+            const uint8_t *packet_end = find_resync_marker_reverse(frame_buf,
+                                                                   frame_buf + cur_frame_size);
+            cur_frame_size = packet_end - frame_buf;
+        }
 
-        memcpy(tmp_buf_ptr, frame_buf, processed_frame_size);
-        tmp_buf_ptr += processed_frame_size;
+        /* calculate the "marker" bit for the RTP header */
+        last_packet_of_frame = cur_frame_size == frame_size;
 
-        ff_rtp_send_data(s1, rtp_ctx->buf, tmp_buf_ptr - rtp_ctx->buf, last_packet_of_frame);
+        /* complete and send RTP packet */
+        memcpy(&rtp_ctx->buf[RTP_H261_HEADER_SIZE], frame_buf, cur_frame_size);
+        ff_rtp_send_data(ctx, rtp_ctx->buf, RTP_H261_HEADER_SIZE + cur_frame_size, last_packet_of_frame);
 
-        frame_buf += processed_frame_size;
-        frame_size -= processed_frame_size;
+        frame_buf  += cur_frame_size;
+        frame_size -= cur_frame_size;
     }
 }
diff --git a/libavformat/sdp.c b/libavformat/sdp.c
index fadabbe..4d621c7 100644
--- a/libavformat/sdp.c
+++ b/libavformat/sdp.c
@@ -504,9 +504,10 @@ static char *sdp_write_media_attributes(char *buff, int size, AVCodecContext *c,
             /* only QCIF and CIF are specified as supported in RFC 4587 */
             if (c->width == 176 && c->height == 144)
                 pic_fmt = "QCIF=1";
-            if (c->width == 352 && c->height == 288)
+            else if (c->width == 352 && c->height == 288)
                 pic_fmt = "CIF=1";
-            av_strlcatf(buff, size, "a=rtpmap:%d H261/90000\r\n", payload_type);
+            if (payload_type >= RTP_PT_PRIVATE)
+                av_strlcatf(buff, size, "a=rtpmap:%d H261/90000\r\n", payload_type);
             if (pic_fmt)
                 av_strlcatf(buff, size, "a=fmtp:%d %s\r\n", payload_type, pic_fmt);
             break;
diff --git a/libavformat/version.h b/libavformat/version.h
index d39dd5d..d3ce0bf 100644
--- a/libavformat/version.h
+++ b/libavformat/version.h
@@ -31,7 +31,7 @@
 
 #define LIBAVFORMAT_VERSION_MAJOR 56
 #define LIBAVFORMAT_VERSION_MINOR  15
-#define LIBAVFORMAT_VERSION_MICRO 106
+#define LIBAVFORMAT_VERSION_MICRO 107
 
 #define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
                                                LIBAVFORMAT_VERSION_MINOR, \