/*************************************************************************** * __________ __ ___. * Open \______ \ ____ ____ | | _\_ |__ _______ ___ * Source | _// _ \_/ ___\| |/ /| __ \ / _ \ \/ / * Jukebox | | ( <_> ) \___| < | \_\ ( <_> > < < * Firmware |____|_ /\____/ \___ >__|_ \|___ /\____/__/\_ \ * \/ \/ \/ \/ \/ * * Copyright (C) 2007 Dave Chapman * * ASF parsing code based on libasf by Juho Vähä-Herttua * http://code.google.com/p/libasf/ libasf itself was based on the ASF * parser in VLC - http://www.videolan.org/ * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation; either version 2 * of the License, or (at your option) any later version. * * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY * KIND, either express or implied. * ****************************************************************************/ #include #include "codeclib.h" #include "asf.h" /* Read an unaligned 32-bit little endian long from buffer. */ static unsigned long get_long_le(void* buf) { unsigned char* p = (unsigned char*) buf; return p[0] | (p[1] << 8) | (p[2] << 16) | (p[3] << 24); } /* Read an unaligned 16-bit little endian short from buffer. */ static unsigned short get_short_le(void* buf) { unsigned char* p = (unsigned char*) buf; return p[0] | (p[1] << 8); } #define GETLEN2b(bits) (((bits) == 0x03) ? 4 : bits) #define GETVALUE2b(bits, data) \ (((bits) != 0x03) ? ((bits) != 0x02) ? ((bits) != 0x01) ? \ 0 : *(data) : get_short_le(data) : get_long_le(data)) int asf_read_packet(uint8_t** audiobuf, int* audiobufsize, int* packetlength, asf_waveformatex_t* wfx) { uint8_t tmp8, packet_flags, packet_property; int stream_id; int ec_length, opaque_data, ec_length_type; int datalen; uint8_t data[18]; uint8_t* datap; uint32_t length; uint32_t padding_length; /* rockbox: comment 'set but unused' variables uint32_t send_time; uint16_t duration; uint32_t media_object_number; uint32_t media_object_offset; */ uint16_t payload_count; int payload_length_type; uint32_t payload_hdrlen; int payload_datalen; int multiple; uint32_t replicated_length; uint32_t bytesread = 0; uint8_t* buf; size_t bufsize; int i; /*DEBUGF("Reading new packet at %d bytes ", (int)ci->curpos);*/ if (ci->read_filebuf(&tmp8, 1) == 0) { return ASF_ERROR_EOF; } bytesread++; /* TODO: We need a better way to detect endofstream */ if (tmp8 != 0x82) { DEBUGF("Read failed: packet did not sync\n"); return -1; } if (tmp8 & 0x80) { ec_length = tmp8 & 0x0f; opaque_data = (tmp8 >> 4) & 0x01; ec_length_type = (tmp8 >> 5) & 0x03; if (ec_length_type != 0x00 || opaque_data != 0 || ec_length != 0x02) { DEBUGF("incorrect error correction flags\n"); return ASF_ERROR_INVALID_VALUE; } /* Skip ec_data */ ci->advance_buffer(ec_length); bytesread += ec_length; } else { ec_length = 0; } if (ci->read_filebuf(&packet_flags, 1) == 0) { return ASF_ERROR_EOF; } if (ci->read_filebuf(&packet_property, 1) == 0) { return ASF_ERROR_EOF; } bytesread += 2; datalen = GETLEN2b((packet_flags >> 1) & 0x03) + GETLEN2b((packet_flags >> 3) & 0x03) + GETLEN2b((packet_flags >> 5) & 0x03) + 6; #if 0 if (datalen > sizeof(data)) { DEBUGF("Unexpectedly long datalen in data - %d\n",datalen); return ASF_ERROR_OUTOFMEM; } #endif if (ci->read_filebuf(data, datalen) == 0) { return ASF_ERROR_EOF; } bytesread += datalen; datap = data; length = GETVALUE2b((packet_flags >> 5) & 0x03, datap); datap += GETLEN2b((packet_flags >> 5) & 0x03); /* sequence value is not used */ GETVALUE2b((packet_flags >> 1) & 0x03, datap); datap += GETLEN2b((packet_flags >> 1) & 0x03); padding_length = GETVALUE2b((packet_flags >> 3) & 0x03, datap); datap += GETLEN2b((packet_flags >> 3) & 0x03); /* send_time = get_long_le(datap); */ datap += 4; /* duration = get_short_le(datap); */ datap += 2; /*DEBUGF("and duration %d ms\n", duration);*/ /* this is really idiotic, packet length can (and often will) be * undefined and we just have to use the header packet size as the size * value */ if (!((packet_flags >> 5) & 0x03)) { length = wfx->packet_size; } /* this is also really idiotic, if packet length is smaller than packet * size, we need to manually add the additional bytes into padding length */ if (length < wfx->packet_size) { padding_length += wfx->packet_size - length; length = wfx->packet_size; } if (length > wfx->packet_size) { DEBUGF("packet with too big length value\n"); return ASF_ERROR_INVALID_LENGTH; } /* check if we have multiple payloads */ if (packet_flags & 0x01) { if (ci->read_filebuf(&tmp8, 1) == 0) { return ASF_ERROR_EOF; } payload_count = tmp8 & 0x3f; payload_length_type = (tmp8 >> 6) & 0x03; bytesread++; } else { payload_count = 1; payload_length_type = 0x02; /* not used */ } if (length < bytesread) { DEBUGF("header exceeded packet size, invalid file - length=%d, bytesread=%d\n",(int)length,(int)bytesread); /* FIXME: should this be checked earlier? */ return ASF_ERROR_INVALID_LENGTH; } /* We now parse the individual payloads, and move all payloads belonging to our audio stream to a contiguous block, starting at the location of the first payload. */ *audiobuf = NULL; *audiobufsize = 0; *packetlength = length - bytesread; buf = ci->request_buffer(&bufsize, length); datap = buf; #define ASF_MAX_REQUEST (1L<<15) /* 32KB */ if (bufsize != length && length >= ASF_MAX_REQUEST) { /* This should only happen with packets larger than 32KB (the guard buffer size). All the streams I've seen have relatively small packets less than about 8KB), but I don't know what is expected. */ DEBUGF("Could not read packet (requested %d bytes, received %d), curpos=%d, aborting\n", (int)length,(int)bufsize,(int)ci->curpos); return -1; } for (i=0; i> 2) & 0x03) + GETLEN2b((packet_property >> 4) & 0x03); //DEBUGF("payload_hdrlen = %d\n",payload_hdrlen); #if 0 /* TODO */ if (payload_hdrlen > size) { return ASF_ERROR_INVALID_LENGTH; } #endif if (payload_hdrlen > sizeof(data)) { DEBUGF("Unexpectedly long datalen in data - %d\n",datalen); return ASF_ERROR_OUTOFMEM; } bytesread += payload_hdrlen; /* media_object_number = GETVALUE2b((packet_property >> 4) & 0x03, datap); */ datap += GETLEN2b((packet_property >> 4) & 0x03); /* media_object_offset = GETVALUE2b((packet_property >> 2) & 0x03, datap); */ datap += GETLEN2b((packet_property >> 2) & 0x03); replicated_length = GETVALUE2b(packet_property & 0x03, datap); datap += GETLEN2b(packet_property & 0x03); /* TODO: Validate replicated_length */ /* TODO: Is the content of this important for us? */ datap += replicated_length; bytesread += replicated_length; multiple = packet_flags & 0x01; if (multiple) { int x; x = GETLEN2b(payload_length_type); if (x != 2) { /* in multiple payloads datalen should be a word */ return ASF_ERROR_INVALID_VALUE; } #if 0 if (skip + tmp > datalen) { /* not enough data */ return ASF_ERROR_INVALID_LENGTH; } #endif payload_datalen = GETVALUE2b(payload_length_type, datap); datap += x; bytesread += x; } else { payload_datalen = length - bytesread - padding_length; } if (replicated_length==1) datap++; if (stream_id == wfx->audiostream) { if (*audiobuf == NULL) { /* The first payload can stay where it is */ *audiobuf = datap; *audiobufsize = payload_datalen; } else { /* The second and subsequent payloads in this packet that belong to the audio stream need to be moved to be contiguous with the first payload. */ memmove(*audiobuf + *audiobufsize, datap, payload_datalen); *audiobufsize += payload_datalen; } } datap += payload_datalen; bytesread += payload_datalen; } if (*audiobuf != NULL) return 1; else return 0; } int asf_get_timestamp(int *duration) { uint8_t tmp8, packet_flags, packet_property; int ec_length, opaque_data, ec_length_type; int datalen; uint8_t data[18]; uint8_t* datap; /* rockbox: comment 'set but unused' variables uint32_t length; uint32_t padding_length; */ uint32_t send_time; // static int packet_count = 0; uint32_t bytesread = 0; // packet_count++; if (ci->read_filebuf(&tmp8, 1) == 0) { DEBUGF("ASF ERROR (EOF?)\n"); return ASF_ERROR_EOF; } bytesread++; /* TODO: We need a better way to detect endofstream */ if (tmp8 != 0x82) { DEBUGF("Get timestamp: Detected end of stream\n"); return ASF_ERROR_EOF; } if (tmp8 & 0x80) { ec_length = tmp8 & 0x0f; opaque_data = (tmp8 >> 4) & 0x01; ec_length_type = (tmp8 >> 5) & 0x03; if (ec_length_type != 0x00 || opaque_data != 0 || ec_length != 0x02) { DEBUGF("incorrect error correction flags\n"); return ASF_ERROR_INVALID_VALUE; } /* Skip ec_data */ ci->advance_buffer(ec_length); bytesread += ec_length; } else { ec_length = 0; } if (ci->read_filebuf(&packet_flags, 1) == 0) { DEBUGF("Detected end of stream 2\n"); return ASF_ERROR_EOF; } if (ci->read_filebuf(&packet_property, 1) == 0) { DEBUGF("Detected end of stream3\n"); return ASF_ERROR_EOF; } bytesread += 2; datalen = GETLEN2b((packet_flags >> 1) & 0x03) + GETLEN2b((packet_flags >> 3) & 0x03) + GETLEN2b((packet_flags >> 5) & 0x03) + 6; if (ci->read_filebuf(data, datalen) == 0) { DEBUGF("Detected end of stream4\n"); return ASF_ERROR_EOF; } bytesread += datalen; datap = data; /* length = GETVALUE2b((packet_flags >> 5) & 0x03, datap); */ datap += GETLEN2b((packet_flags >> 5) & 0x03); /* sequence value is not used */ GETVALUE2b((packet_flags >> 1) & 0x03, datap); datap += GETLEN2b((packet_flags >> 1) & 0x03); /* padding_length = GETVALUE2b((packet_flags >> 3) & 0x03, datap); */ datap += GETLEN2b((packet_flags >> 3) & 0x03); send_time = get_long_le(datap); datap += 4; *duration = get_short_le(datap); /*the asf_get_timestamp function advances us 12-13 bytes past the packet start, need to undo this here so that we stay synced with the packet*/ ci->seek_buffer(ci->curpos-bytesread); return send_time; } /*entry point for seeks*/ int asf_seek(int ms, asf_waveformatex_t* wfx) { int time, duration, delta, temp, count=0; int bitrate = ci->id3->bitrate*1000/8; /*estimate packet number from bitrate*/ int initial_packet = ci->curpos/wfx->packet_size; int packet_num = (((int64_t)ms)*(bitrate))/wfx->packet_size/1000; /*subtract header size in case theres a lot of metadata*/ int last_packet = (ci->id3->filesize-ci->id3->first_frame_offset) / wfx->packet_size; /* DEBUGF("bitrate: %d\n", bitrate); DEBUGF("attempting seek to: %d ms, initialp: %d, lastp: %d, estimating packet: %d, packet size: %d\n", ms, initial_packet, last_packet, packet_num, wfx->packet_size);*/ if (packet_num > last_packet) { packet_num = last_packet; } /*calculate byte address of the start of that packet*/ int packet_offset = packet_num*wfx->packet_size; /*seek to estimated packet*/ ci->seek_buffer(ci->id3->first_frame_offset+packet_offset); temp = ms; while (1) { /*for very large files it can be difficult and unimportant to find the exact packet*/ count++; /*check the time stamp of our packet*/ time = asf_get_timestamp(&duration); /*DEBUGF("seeked to %d ms (%d) with duration %d\n", time,packet_num, duration);*/ if (time < 0) { /*unknown error, try to recover*/ DEBUGF("UKNOWN SEEK ERROR\n"); ci->seek_buffer(ci->id3->first_frame_offset+initial_packet*wfx->packet_size); /*seek failed so return time stamp of the initial packet*/ return asf_get_timestamp(&duration); } if ((time+duration>=ms && time<=ms) || count > 10) { /*DEBUGF("Found our packet! Now at %d packet\n", packet_num);*/ return time; } else { /*seek again*/ delta = ms-time; /*estimate new packet number from bitrate and our current position*/ temp += delta; packet_num = ((temp/1000)*(bitrate) - (wfx->packet_size<<1))/wfx->packet_size; //round down! packet_offset = packet_num*wfx->packet_size; ci->seek_buffer(ci->id3->first_frame_offset+packet_offset); } } }