• Main Page
  • Related Pages
  • Modules
  • Data Structures
  • Files
  • Examples
  • File List
  • Globals

libavformat/rtmppkt.c

Go to the documentation of this file.
00001 /*
00002  * RTMP input format
00003  * Copyright (c) 2009 Kostya Shishkov
00004  *
00005  * This file is part of FFmpeg.
00006  *
00007  * FFmpeg is free software; you can redistribute it and/or
00008  * modify it under the terms of the GNU Lesser General Public
00009  * License as published by the Free Software Foundation; either
00010  * version 2.1 of the License, or (at your option) any later version.
00011  *
00012  * FFmpeg is distributed in the hope that it will be useful,
00013  * but WITHOUT ANY WARRANTY; without even the implied warranty of
00014  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
00015  * Lesser General Public License for more details.
00016  *
00017  * You should have received a copy of the GNU Lesser General Public
00018  * License along with FFmpeg; if not, write to the Free Software
00019  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
00020  */
00021 
00022 #include "libavcodec/bytestream.h"
00023 #include "libavutil/avstring.h"
00024 #include "avformat.h"
00025 
00026 #include "rtmppkt.h"
00027 #include "flv.h"
00028 #include "url.h"
00029 
00030 void ff_amf_write_bool(uint8_t **dst, int val)
00031 {
00032     bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
00033     bytestream_put_byte(dst, val);
00034 }
00035 
00036 void ff_amf_write_number(uint8_t **dst, double val)
00037 {
00038     bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
00039     bytestream_put_be64(dst, av_dbl2int(val));
00040 }
00041 
00042 void ff_amf_write_string(uint8_t **dst, const char *str)
00043 {
00044     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
00045     bytestream_put_be16(dst, strlen(str));
00046     bytestream_put_buffer(dst, str, strlen(str));
00047 }
00048 
00049 void ff_amf_write_null(uint8_t **dst)
00050 {
00051     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
00052 }
00053 
00054 void ff_amf_write_object_start(uint8_t **dst)
00055 {
00056     bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
00057 }
00058 
00059 void ff_amf_write_field_name(uint8_t **dst, const char *str)
00060 {
00061     bytestream_put_be16(dst, strlen(str));
00062     bytestream_put_buffer(dst, str, strlen(str));
00063 }
00064 
00065 void ff_amf_write_object_end(uint8_t **dst)
00066 {
00067     /* first two bytes are field name length = 0,
00068      * AMF object should end with it and end marker
00069      */
00070     bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
00071 }
00072 
00073 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
00074                         int chunk_size, RTMPPacket *prev_pkt)
00075 {
00076     uint8_t hdr, t, buf[16];
00077     int channel_id, timestamp, data_size, offset = 0;
00078     uint32_t extra = 0;
00079     enum RTMPPacketType type;
00080     int size = 0;
00081 
00082     if (ffurl_read(h, &hdr, 1) != 1)
00083         return AVERROR(EIO);
00084     size++;
00085     channel_id = hdr & 0x3F;
00086 
00087     if (channel_id < 2) { //special case for channel number >= 64
00088         buf[1] = 0;
00089         if (ffurl_read_complete(h, buf, channel_id + 1) != channel_id + 1)
00090             return AVERROR(EIO);
00091         size += channel_id + 1;
00092         channel_id = AV_RL16(buf) + 64;
00093     }
00094     data_size = prev_pkt[channel_id].data_size;
00095     type      = prev_pkt[channel_id].type;
00096     extra     = prev_pkt[channel_id].extra;
00097 
00098     hdr >>= 6;
00099     if (hdr == RTMP_PS_ONEBYTE) {
00100         timestamp = prev_pkt[channel_id].ts_delta;
00101     } else {
00102         if (ffurl_read_complete(h, buf, 3) != 3)
00103             return AVERROR(EIO);
00104         size += 3;
00105         timestamp = AV_RB24(buf);
00106         if (hdr != RTMP_PS_FOURBYTES) {
00107             if (ffurl_read_complete(h, buf, 3) != 3)
00108                 return AVERROR(EIO);
00109             size += 3;
00110             data_size = AV_RB24(buf);
00111             if (ffurl_read_complete(h, buf, 1) != 1)
00112                 return AVERROR(EIO);
00113             size++;
00114             type = buf[0];
00115             if (hdr == RTMP_PS_TWELVEBYTES) {
00116                 if (ffurl_read_complete(h, buf, 4) != 4)
00117                     return AVERROR(EIO);
00118                 size += 4;
00119                 extra = AV_RL32(buf);
00120             }
00121         }
00122         if (timestamp == 0xFFFFFF) {
00123             if (ffurl_read_complete(h, buf, 4) != 4)
00124                 return AVERROR(EIO);
00125             timestamp = AV_RB32(buf);
00126         }
00127     }
00128     if (hdr != RTMP_PS_TWELVEBYTES)
00129         timestamp += prev_pkt[channel_id].timestamp;
00130 
00131     if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
00132         return -1;
00133     p->extra = extra;
00134     // save history
00135     prev_pkt[channel_id].channel_id = channel_id;
00136     prev_pkt[channel_id].type       = type;
00137     prev_pkt[channel_id].data_size  = data_size;
00138     prev_pkt[channel_id].ts_delta   = timestamp - prev_pkt[channel_id].timestamp;
00139     prev_pkt[channel_id].timestamp  = timestamp;
00140     prev_pkt[channel_id].extra      = extra;
00141     while (data_size > 0) {
00142         int toread = FFMIN(data_size, chunk_size);
00143         if (ffurl_read_complete(h, p->data + offset, toread) != toread) {
00144             ff_rtmp_packet_destroy(p);
00145             return AVERROR(EIO);
00146         }
00147         data_size -= chunk_size;
00148         offset    += chunk_size;
00149         size      += chunk_size;
00150         if (data_size > 0) {
00151             ffurl_read_complete(h, &t, 1); //marker
00152             size++;
00153             if (t != (0xC0 + channel_id))
00154                 return -1;
00155         }
00156     }
00157     return size;
00158 }
00159 
00160 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
00161                          int chunk_size, RTMPPacket *prev_pkt)
00162 {
00163     uint8_t pkt_hdr[16], *p = pkt_hdr;
00164     int mode = RTMP_PS_TWELVEBYTES;
00165     int off = 0;
00166     int size = 0;
00167 
00168     pkt->ts_delta = pkt->timestamp - prev_pkt[pkt->channel_id].timestamp;
00169 
00170     //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
00171     if (prev_pkt[pkt->channel_id].channel_id &&
00172         pkt->extra == prev_pkt[pkt->channel_id].extra) {
00173         if (pkt->type == prev_pkt[pkt->channel_id].type &&
00174             pkt->data_size == prev_pkt[pkt->channel_id].data_size) {
00175             mode = RTMP_PS_FOURBYTES;
00176             if (pkt->ts_delta == prev_pkt[pkt->channel_id].ts_delta)
00177                 mode = RTMP_PS_ONEBYTE;
00178         } else {
00179             mode = RTMP_PS_EIGHTBYTES;
00180         }
00181     }
00182 
00183     if (pkt->channel_id < 64) {
00184         bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
00185     } else if (pkt->channel_id < 64 + 256) {
00186         bytestream_put_byte(&p, 0               | (mode << 6));
00187         bytestream_put_byte(&p, pkt->channel_id - 64);
00188     } else {
00189         bytestream_put_byte(&p, 1               | (mode << 6));
00190         bytestream_put_le16(&p, pkt->channel_id - 64);
00191     }
00192     if (mode != RTMP_PS_ONEBYTE) {
00193         uint32_t timestamp = pkt->timestamp;
00194         if (mode != RTMP_PS_TWELVEBYTES)
00195             timestamp = pkt->ts_delta;
00196         bytestream_put_be24(&p, timestamp >= 0xFFFFFF ? 0xFFFFFF : timestamp);
00197         if (mode != RTMP_PS_FOURBYTES) {
00198             bytestream_put_be24(&p, pkt->data_size);
00199             bytestream_put_byte(&p, pkt->type);
00200             if (mode == RTMP_PS_TWELVEBYTES)
00201                 bytestream_put_le32(&p, pkt->extra);
00202         }
00203         if (timestamp >= 0xFFFFFF)
00204             bytestream_put_be32(&p, timestamp);
00205     }
00206     // save history
00207     prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
00208     prev_pkt[pkt->channel_id].type       = pkt->type;
00209     prev_pkt[pkt->channel_id].data_size  = pkt->data_size;
00210     prev_pkt[pkt->channel_id].timestamp  = pkt->timestamp;
00211     if (mode != RTMP_PS_TWELVEBYTES) {
00212         prev_pkt[pkt->channel_id].ts_delta   = pkt->ts_delta;
00213     } else {
00214         prev_pkt[pkt->channel_id].ts_delta   = pkt->timestamp;
00215     }
00216     prev_pkt[pkt->channel_id].extra      = pkt->extra;
00217 
00218     ffurl_write(h, pkt_hdr, p-pkt_hdr);
00219     size = p - pkt_hdr + pkt->data_size;
00220     while (off < pkt->data_size) {
00221         int towrite = FFMIN(chunk_size, pkt->data_size - off);
00222         ffurl_write(h, pkt->data + off, towrite);
00223         off += towrite;
00224         if (off < pkt->data_size) {
00225             uint8_t marker = 0xC0 | pkt->channel_id;
00226             ffurl_write(h, &marker, 1);
00227             size++;
00228         }
00229     }
00230     return size;
00231 }
00232 
00233 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
00234                           int timestamp, int size)
00235 {
00236     if (size) {
00237         pkt->data = av_malloc(size);
00238         if (!pkt->data)
00239             return AVERROR(ENOMEM);
00240     }
00241     pkt->data_size  = size;
00242     pkt->channel_id = channel_id;
00243     pkt->type       = type;
00244     pkt->timestamp  = timestamp;
00245     pkt->extra      = 0;
00246     pkt->ts_delta   = 0;
00247 
00248     return 0;
00249 }
00250 
00251 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
00252 {
00253     if (!pkt)
00254         return;
00255     av_freep(&pkt->data);
00256     pkt->data_size = 0;
00257 }
00258 
00259 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
00260 {
00261     const uint8_t *base = data;
00262 
00263     if (data >= data_end)
00264         return -1;
00265     switch (*data++) {
00266     case AMF_DATA_TYPE_NUMBER:      return 9;
00267     case AMF_DATA_TYPE_BOOL:        return 2;
00268     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
00269     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
00270     case AMF_DATA_TYPE_NULL:        return 1;
00271     case AMF_DATA_TYPE_ARRAY:
00272         data += 4;
00273     case AMF_DATA_TYPE_OBJECT:
00274         for (;;) {
00275             int size = bytestream_get_be16(&data);
00276             int t;
00277             if (!size) {
00278                 data++;
00279                 break;
00280             }
00281             if (size < 0 || size >= data_end - data)
00282                 return -1;
00283             data += size;
00284             t = ff_amf_tag_size(data, data_end);
00285             if (t < 0 || t >= data_end - data)
00286                 return -1;
00287             data += t;
00288         }
00289         return data - base;
00290     case AMF_DATA_TYPE_OBJECT_END:  return 1;
00291     default:                        return -1;
00292     }
00293 }
00294 
00295 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
00296                            const uint8_t *name, uint8_t *dst, int dst_size)
00297 {
00298     int namelen = strlen(name);
00299     int len;
00300 
00301     while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
00302         len = ff_amf_tag_size(data, data_end);
00303         if (len < 0)
00304             len = data_end - data;
00305         data += len;
00306     }
00307     if (data_end - data < 3)
00308         return -1;
00309     data++;
00310     for (;;) {
00311         int size = bytestream_get_be16(&data);
00312         if (!size)
00313             break;
00314         if (size < 0 || size >= data_end - data)
00315             return -1;
00316         data += size;
00317         if (size == namelen && !memcmp(data-size, name, namelen)) {
00318             switch (*data++) {
00319             case AMF_DATA_TYPE_NUMBER:
00320                 snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
00321                 break;
00322             case AMF_DATA_TYPE_BOOL:
00323                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
00324                 break;
00325             case AMF_DATA_TYPE_STRING:
00326                 len = bytestream_get_be16(&data);
00327                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
00328                 break;
00329             default:
00330                 return -1;
00331             }
00332             return 0;
00333         }
00334         len = ff_amf_tag_size(data, data_end);
00335         if (len < 0 || len >= data_end - data)
00336             return -1;
00337         data += len;
00338     }
00339     return -1;
00340 }
00341 
00342 static const char* rtmp_packet_type(int type)
00343 {
00344     switch (type) {
00345     case RTMP_PT_CHUNK_SIZE:     return "chunk size";
00346     case RTMP_PT_BYTES_READ:     return "bytes read";
00347     case RTMP_PT_PING:           return "ping";
00348     case RTMP_PT_SERVER_BW:      return "server bandwidth";
00349     case RTMP_PT_CLIENT_BW:      return "client bandwidth";
00350     case RTMP_PT_AUDIO:          return "audio packet";
00351     case RTMP_PT_VIDEO:          return "video packet";
00352     case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
00353     case RTMP_PT_FLEX_OBJECT:    return "Flex shared object";
00354     case RTMP_PT_FLEX_MESSAGE:   return "Flex shared message";
00355     case RTMP_PT_NOTIFY:         return "notification";
00356     case RTMP_PT_SHARED_OBJ:     return "shared object";
00357     case RTMP_PT_INVOKE:         return "invoke";
00358     case RTMP_PT_METADATA:       return "metadata";
00359     default:                     return "unknown";
00360     }
00361 }
00362 
00363 static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *data_end)
00364 {
00365     unsigned int size;
00366     char buf[1024];
00367 
00368     if (data >= data_end)
00369         return;
00370     switch (*data++) {
00371     case AMF_DATA_TYPE_NUMBER:
00372         av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2dbl(AV_RB64(data)));
00373         return;
00374     case AMF_DATA_TYPE_BOOL:
00375         av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
00376         return;
00377     case AMF_DATA_TYPE_STRING:
00378     case AMF_DATA_TYPE_LONG_STRING:
00379         if (data[-1] == AMF_DATA_TYPE_STRING) {
00380             size = bytestream_get_be16(&data);
00381         } else {
00382             size = bytestream_get_be32(&data);
00383         }
00384         size = FFMIN(size, sizeof(buf) - 1);
00385         memcpy(buf, data, size);
00386         buf[size] = 0;
00387         av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
00388         return;
00389     case AMF_DATA_TYPE_NULL:
00390         av_log(ctx, AV_LOG_DEBUG, " NULL\n");
00391         return;
00392     case AMF_DATA_TYPE_ARRAY:
00393         data += 4;
00394     case AMF_DATA_TYPE_OBJECT:
00395         av_log(ctx, AV_LOG_DEBUG, " {\n");
00396         for (;;) {
00397             int t;
00398             size = bytestream_get_be16(&data);
00399             av_strlcpy(buf, data, FFMIN(sizeof(buf), size + 1));
00400             if (!size) {
00401                 av_log(ctx, AV_LOG_DEBUG, " }\n");
00402                 data++;
00403                 break;
00404             }
00405             if (size >= data_end - data)
00406                 return;
00407             data += size;
00408             av_log(ctx, AV_LOG_DEBUG, "  %s: ", buf);
00409             ff_amf_tag_contents(ctx, data, data_end);
00410             t = ff_amf_tag_size(data, data_end);
00411             if (t < 0 || t >= data_end - data)
00412                 return;
00413             data += t;
00414         }
00415         return;
00416     case AMF_DATA_TYPE_OBJECT_END:
00417         av_log(ctx, AV_LOG_DEBUG, " }\n");
00418         return;
00419     default:
00420         return;
00421     }
00422 }
00423 
00424 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
00425 {
00426     av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
00427            rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->data_size);
00428     if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
00429         uint8_t *src = p->data, *src_end = p->data + p->data_size;
00430         while (src < src_end) {
00431             int sz;
00432             ff_amf_tag_contents(ctx, src, src_end);
00433             sz = ff_amf_tag_size(src, src_end);
00434             if (sz < 0)
00435                 break;
00436             src += sz;
00437         }
00438     } else if (p->type == RTMP_PT_SERVER_BW){
00439         av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
00440     } else if (p->type == RTMP_PT_CLIENT_BW){
00441         av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
00442     } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
00443         int i;
00444         for (i = 0; i < p->data_size; i++)
00445             av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
00446         av_log(ctx, AV_LOG_DEBUG, "\n");
00447     }
00448 }

Generated on Fri Feb 22 2013 07:24:32 for FFmpeg by  doxygen 1.7.1