FFmpeg: libavformat/rtmppkt.c Source 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 
00029 void ff_amf_write_bool(uint8_t **dst, int val)
00030 {
00031     bytestream_put_byte(dst, AMF_DATA_TYPE_BOOL);
00032     bytestream_put_byte(dst, val);
00033 }
00034 
00035 void ff_amf_write_number(uint8_t **dst, double val)
00036 {
00037     bytestream_put_byte(dst, AMF_DATA_TYPE_NUMBER);
00038     bytestream_put_be64(dst, av_dbl2int(val));
00039 }
00040 
00041 void ff_amf_write_string(uint8_t **dst, const char *str)
00042 {
00043     bytestream_put_byte(dst, AMF_DATA_TYPE_STRING);
00044     bytestream_put_be16(dst, strlen(str));
00045     bytestream_put_buffer(dst, str, strlen(str));
00046 }
00047 
00048 void ff_amf_write_null(uint8_t **dst)
00049 {
00050     bytestream_put_byte(dst, AMF_DATA_TYPE_NULL);
00051 }
00052 
00053 void ff_amf_write_object_start(uint8_t **dst)
00054 {
00055     bytestream_put_byte(dst, AMF_DATA_TYPE_OBJECT);
00056 }
00057 
00058 void ff_amf_write_field_name(uint8_t **dst, const char *str)
00059 {
00060     bytestream_put_be16(dst, strlen(str));
00061     bytestream_put_buffer(dst, str, strlen(str));
00062 }
00063 
00064 void ff_amf_write_object_end(uint8_t **dst)
00065 {
00066     /* first two bytes are field name length = 0,
00067      * AMF object should end with it and end marker
00068      */
00069     bytestream_put_be24(dst, AMF_DATA_TYPE_OBJECT_END);
00070 }
00071 
00072 int ff_rtmp_packet_read(URLContext *h, RTMPPacket *p,
00073                         int chunk_size, RTMPPacket *prev_pkt)
00074 {
00075     uint8_t hdr, t, buf[16];
00076     int channel_id, timestamp, data_size, offset = 0;
00077     uint32_t extra = 0;
00078     enum RTMPPacketType type;
00079     int size = 0;
00080 
00081     if (url_read(h, &hdr, 1) != 1)
00082         return AVERROR(EIO);
00083     size++;
00084     channel_id = hdr & 0x3F;
00085 
00086     if (channel_id < 2) { //special case for channel number >= 64
00087         buf[1] = 0;
00088         if (url_read_complete(h, buf, channel_id + 1) != channel_id + 1)
00089             return AVERROR(EIO);
00090         size += channel_id + 1;
00091         channel_id = AV_RL16(buf) + 64;
00092     }
00093     data_size = prev_pkt[channel_id].data_size;
00094     type      = prev_pkt[channel_id].type;
00095     extra     = prev_pkt[channel_id].extra;
00096 
00097     hdr >>= 6;
00098     if (hdr == RTMP_PS_ONEBYTE) {
00099         timestamp = prev_pkt[channel_id].ts_delta;
00100     } else {
00101         if (url_read_complete(h, buf, 3) != 3)
00102             return AVERROR(EIO);
00103         size += 3;
00104         timestamp = AV_RB24(buf);
00105         if (hdr != RTMP_PS_FOURBYTES) {
00106             if (url_read_complete(h, buf, 3) != 3)
00107                 return AVERROR(EIO);
00108             size += 3;
00109             data_size = AV_RB24(buf);
00110             if (url_read_complete(h, buf, 1) != 1)
00111                 return AVERROR(EIO);
00112             size++;
00113             type = buf[0];
00114             if (hdr == RTMP_PS_TWELVEBYTES) {
00115                 if (url_read_complete(h, buf, 4) != 4)
00116                     return AVERROR(EIO);
00117                 size += 4;
00118                 extra = AV_RL32(buf);
00119             }
00120         }
00121         if (timestamp == 0xFFFFFF) {
00122             if (url_read_complete(h, buf, 4) != 4)
00123                 return AVERROR(EIO);
00124             timestamp = AV_RB32(buf);
00125         }
00126     }
00127     if (hdr != RTMP_PS_TWELVEBYTES)
00128         timestamp += prev_pkt[channel_id].timestamp;
00129 
00130     if (ff_rtmp_packet_create(p, channel_id, type, timestamp, data_size))
00131         return -1;
00132     p->extra = extra;
00133     // save history
00134     prev_pkt[channel_id].channel_id = channel_id;
00135     prev_pkt[channel_id].type       = type;
00136     prev_pkt[channel_id].data_size  = data_size;
00137     prev_pkt[channel_id].ts_delta   = timestamp - prev_pkt[channel_id].timestamp;
00138     prev_pkt[channel_id].timestamp  = timestamp;
00139     prev_pkt[channel_id].extra      = extra;
00140     while (data_size > 0) {
00141         int toread = FFMIN(data_size, chunk_size);
00142         if (url_read_complete(h, p->data + offset, toread) != toread) {
00143             ff_rtmp_packet_destroy(p);
00144             return AVERROR(EIO);
00145         }
00146         data_size -= chunk_size;
00147         offset    += chunk_size;
00148         size      += chunk_size;
00149         if (data_size > 0) {
00150             url_read_complete(h, &t, 1); //marker
00151             size++;
00152             if (t != (0xC0 + channel_id))
00153                 return -1;
00154         }
00155     }
00156     return size;
00157 }
00158 
00159 int ff_rtmp_packet_write(URLContext *h, RTMPPacket *pkt,
00160                          int chunk_size, RTMPPacket *prev_pkt)
00161 {
00162     uint8_t pkt_hdr[16], *p = pkt_hdr;
00163     int mode = RTMP_PS_TWELVEBYTES;
00164     int off = 0;
00165     int size = 0;
00166 
00167     pkt->ts_delta = pkt->timestamp - prev_pkt[pkt->channel_id].timestamp;
00168 
00169     //if channel_id = 0, this is first presentation of prev_pkt, send full hdr.
00170     if (prev_pkt[pkt->channel_id].channel_id &&
00171         pkt->extra == prev_pkt[pkt->channel_id].extra) {
00172         if (pkt->type == prev_pkt[pkt->channel_id].type &&
00173             pkt->data_size == prev_pkt[pkt->channel_id].data_size) {
00174             mode = RTMP_PS_FOURBYTES;
00175             if (pkt->ts_delta == prev_pkt[pkt->channel_id].ts_delta)
00176                 mode = RTMP_PS_ONEBYTE;
00177         } else {
00178             mode = RTMP_PS_EIGHTBYTES;
00179         }
00180     }
00181 
00182     if (pkt->channel_id < 64) {
00183         bytestream_put_byte(&p, pkt->channel_id | (mode << 6));
00184     } else if (pkt->channel_id < 64 + 256) {
00185         bytestream_put_byte(&p, 0               | (mode << 6));
00186         bytestream_put_byte(&p, pkt->channel_id - 64);
00187     } else {
00188         bytestream_put_byte(&p, 1               | (mode << 6));
00189         bytestream_put_le16(&p, pkt->channel_id - 64);
00190     }
00191     if (mode != RTMP_PS_ONEBYTE) {
00192         uint32_t timestamp = pkt->timestamp;
00193         if (mode != RTMP_PS_TWELVEBYTES)
00194             timestamp = pkt->ts_delta;
00195         bytestream_put_be24(&p, timestamp >= 0xFFFFFF ? 0xFFFFFF : timestamp);
00196         if (mode != RTMP_PS_FOURBYTES) {
00197             bytestream_put_be24(&p, pkt->data_size);
00198             bytestream_put_byte(&p, pkt->type);
00199             if (mode == RTMP_PS_TWELVEBYTES)
00200                 bytestream_put_le32(&p, pkt->extra);
00201         }
00202         if (timestamp >= 0xFFFFFF)
00203             bytestream_put_be32(&p, timestamp);
00204     }
00205     // save history
00206     prev_pkt[pkt->channel_id].channel_id = pkt->channel_id;
00207     prev_pkt[pkt->channel_id].type       = pkt->type;
00208     prev_pkt[pkt->channel_id].data_size  = pkt->data_size;
00209     prev_pkt[pkt->channel_id].timestamp  = pkt->timestamp;
00210     if (mode != RTMP_PS_TWELVEBYTES) {
00211         prev_pkt[pkt->channel_id].ts_delta   = pkt->ts_delta;
00212     } else {
00213         prev_pkt[pkt->channel_id].ts_delta   = pkt->timestamp;
00214     }
00215     prev_pkt[pkt->channel_id].extra      = pkt->extra;
00216 
00217     url_write(h, pkt_hdr, p-pkt_hdr);
00218     size = p - pkt_hdr + pkt->data_size;
00219     while (off < pkt->data_size) {
00220         int towrite = FFMIN(chunk_size, pkt->data_size - off);
00221         url_write(h, pkt->data + off, towrite);
00222         off += towrite;
00223         if (off < pkt->data_size) {
00224             uint8_t marker = 0xC0 | pkt->channel_id;
00225             url_write(h, &marker, 1);
00226             size++;
00227         }
00228     }
00229     return size;
00230 }
00231 
00232 int ff_rtmp_packet_create(RTMPPacket *pkt, int channel_id, RTMPPacketType type,
00233                           int timestamp, int size)
00234 {
00235     pkt->data = av_malloc(size);
00236     if (!pkt->data)
00237         return AVERROR(ENOMEM);
00238     pkt->data_size  = size;
00239     pkt->channel_id = channel_id;
00240     pkt->type       = type;
00241     pkt->timestamp  = timestamp;
00242     pkt->extra      = 0;
00243     pkt->ts_delta   = 0;
00244 
00245     return 0;
00246 }
00247 
00248 void ff_rtmp_packet_destroy(RTMPPacket *pkt)
00249 {
00250     if (!pkt)
00251         return;
00252     av_freep(&pkt->data);
00253     pkt->data_size = 0;
00254 }
00255 
00256 int ff_amf_tag_size(const uint8_t *data, const uint8_t *data_end)
00257 {
00258     const uint8_t *base = data;
00259 
00260     if (data >= data_end)
00261         return -1;
00262     switch (*data++) {
00263     case AMF_DATA_TYPE_NUMBER:      return 9;
00264     case AMF_DATA_TYPE_BOOL:        return 2;
00265     case AMF_DATA_TYPE_STRING:      return 3 + AV_RB16(data);
00266     case AMF_DATA_TYPE_LONG_STRING: return 5 + AV_RB32(data);
00267     case AMF_DATA_TYPE_NULL:        return 1;
00268     case AMF_DATA_TYPE_ARRAY:
00269         data += 4;
00270     case AMF_DATA_TYPE_OBJECT:
00271         for (;;) {
00272             int size = bytestream_get_be16(&data);
00273             int t;
00274             if (!size) {
00275                 data++;
00276                 break;
00277             }
00278             if (data + size >= data_end || data + size < data)
00279                 return -1;
00280             data += size;
00281             t = ff_amf_tag_size(data, data_end);
00282             if (t < 0 || data + t >= data_end)
00283                 return -1;
00284             data += t;
00285         }
00286         return data - base;
00287     case AMF_DATA_TYPE_OBJECT_END:  return 1;
00288     default:                        return -1;
00289     }
00290 }
00291 
00292 int ff_amf_get_field_value(const uint8_t *data, const uint8_t *data_end,
00293                            const uint8_t *name, uint8_t *dst, int dst_size)
00294 {
00295     int namelen = strlen(name);
00296     int len;
00297 
00298     while (*data != AMF_DATA_TYPE_OBJECT && data < data_end) {
00299         len = ff_amf_tag_size(data, data_end);
00300         if (len < 0)
00301             len = data_end - data;
00302         data += len;
00303     }
00304     if (data_end - data < 3)
00305         return -1;
00306     data++;
00307     for (;;) {
00308         int size = bytestream_get_be16(&data);
00309         if (!size)
00310             break;
00311         if (data + size >= data_end || data + size < data)
00312             return -1;
00313         data += size;
00314         if (size == namelen && !memcmp(data-size, name, namelen)) {
00315             switch (*data++) {
00316             case AMF_DATA_TYPE_NUMBER:
00317                 snprintf(dst, dst_size, "%g", av_int2dbl(AV_RB64(data)));
00318                 break;
00319             case AMF_DATA_TYPE_BOOL:
00320                 snprintf(dst, dst_size, "%s", *data ? "true" : "false");
00321                 break;
00322             case AMF_DATA_TYPE_STRING:
00323                 len = bytestream_get_be16(&data);
00324                 av_strlcpy(dst, data, FFMIN(len+1, dst_size));
00325                 break;
00326             default:
00327                 return -1;
00328             }
00329             return 0;
00330         }
00331         len = ff_amf_tag_size(data, data_end);
00332         if (len < 0 || data + len >= data_end || data + len < data)
00333             return -1;
00334         data += len;
00335     }
00336     return -1;
00337 }
00338 
00339 static const char* rtmp_packet_type(int type)
00340 {
00341     switch (type) {
00342     case RTMP_PT_CHUNK_SIZE:     return "chunk size";
00343     case RTMP_PT_BYTES_READ:     return "bytes read";
00344     case RTMP_PT_PING:           return "ping";
00345     case RTMP_PT_SERVER_BW:      return "server bandwidth";
00346     case RTMP_PT_CLIENT_BW:      return "client bandwidth";
00347     case RTMP_PT_AUDIO:          return "audio packet";
00348     case RTMP_PT_VIDEO:          return "video packet";
00349     case RTMP_PT_FLEX_STREAM:    return "Flex shared stream";
00350     case RTMP_PT_FLEX_OBJECT:    return "Flex shared object";
00351     case RTMP_PT_FLEX_MESSAGE:   return "Flex shared message";
00352     case RTMP_PT_NOTIFY:         return "notification";
00353     case RTMP_PT_SHARED_OBJ:     return "shared object";
00354     case RTMP_PT_INVOKE:         return "invoke";
00355     case RTMP_PT_METADATA:       return "metadata";
00356     default:                     return "unknown";
00357     }
00358 }
00359 
00360 static void ff_amf_tag_contents(void *ctx, const uint8_t *data, const uint8_t *data_end)
00361 {
00362     int size;
00363     char buf[1024];
00364 
00365     if (data >= data_end)
00366         return;
00367     switch (*data++) {
00368     case AMF_DATA_TYPE_NUMBER:
00369         av_log(ctx, AV_LOG_DEBUG, " number %g\n", av_int2dbl(AV_RB64(data)));
00370         return;
00371     case AMF_DATA_TYPE_BOOL:
00372         av_log(ctx, AV_LOG_DEBUG, " bool %d\n", *data);
00373         return;
00374     case AMF_DATA_TYPE_STRING:
00375     case AMF_DATA_TYPE_LONG_STRING:
00376         if (data[-1] == AMF_DATA_TYPE_STRING) {
00377             size = bytestream_get_be16(&data);
00378         } else {
00379             size = bytestream_get_be32(&data);
00380         }
00381         size = FFMIN(size, 1023);
00382         memcpy(buf, data, size);
00383         buf[size] = 0;
00384         av_log(ctx, AV_LOG_DEBUG, " string '%s'\n", buf);
00385         return;
00386     case AMF_DATA_TYPE_NULL:
00387         av_log(ctx, AV_LOG_DEBUG, " NULL\n");
00388         return;
00389     case AMF_DATA_TYPE_ARRAY:
00390         data += 4;
00391     case AMF_DATA_TYPE_OBJECT:
00392         av_log(ctx, AV_LOG_DEBUG, " {\n");
00393         for (;;) {
00394             int size = bytestream_get_be16(&data);
00395             int t;
00396             memcpy(buf, data, size);
00397             buf[size] = 0;
00398             if (!size) {
00399                 av_log(ctx, AV_LOG_DEBUG, " }\n");
00400                 data++;
00401                 break;
00402             }
00403             if (data + size >= data_end || data + size < data)
00404                 return;
00405             data += size;
00406             av_log(ctx, AV_LOG_DEBUG, "  %s: ", buf);
00407             ff_amf_tag_contents(ctx, data, data_end);
00408             t = ff_amf_tag_size(data, data_end);
00409             if (t < 0 || data + t >= data_end)
00410                 return;
00411             data += t;
00412         }
00413         return;
00414     case AMF_DATA_TYPE_OBJECT_END:
00415         av_log(ctx, AV_LOG_DEBUG, " }\n");
00416         return;
00417     default:
00418         return;
00419     }
00420 }
00421 
00422 void ff_rtmp_packet_dump(void *ctx, RTMPPacket *p)
00423 {
00424     av_log(ctx, AV_LOG_DEBUG, "RTMP packet type '%s'(%d) for channel %d, timestamp %d, extra field %d size %d\n",
00425            rtmp_packet_type(p->type), p->type, p->channel_id, p->timestamp, p->extra, p->data_size);
00426     if (p->type == RTMP_PT_INVOKE || p->type == RTMP_PT_NOTIFY) {
00427         uint8_t *src = p->data, *src_end = p->data + p->data_size;
00428         while (src < src_end) {
00429             int sz;
00430             ff_amf_tag_contents(ctx, src, src_end);
00431             sz = ff_amf_tag_size(src, src_end);
00432             if (sz < 0)
00433                 break;
00434             src += sz;
00435         }
00436     } else if (p->type == RTMP_PT_SERVER_BW){
00437         av_log(ctx, AV_LOG_DEBUG, "Server BW = %d\n", AV_RB32(p->data));
00438     } else if (p->type == RTMP_PT_CLIENT_BW){
00439         av_log(ctx, AV_LOG_DEBUG, "Client BW = %d\n", AV_RB32(p->data));
00440     } else if (p->type != RTMP_PT_AUDIO && p->type != RTMP_PT_VIDEO && p->type != RTMP_PT_METADATA) {
00441         int i;
00442         for (i = 0; i < p->data_size; i++)
00443             av_log(ctx, AV_LOG_DEBUG, " %02X", p->data[i]);
00444         av_log(ctx, AV_LOG_DEBUG, "\n");
00445     }
00446 }