From 792ae6b1bd7ec85f2ab8eec34dad1d22b05a213e Mon Sep 17 00:00:00 2001 From: Mohamed Tarek Date: Sun, 2 May 2010 17:19:42 +0000 Subject: - Factor out container specific code from apps/codecs/wma.c. - Create an independent asf packet-parsing library in apps/codecs/libasf. - Modify wma.c to use the newly created libasf. git-svn-id: svn://svn.rockbox.org/rockbox/trunk@25780 a1c6a512-1295-4272-9138-f99709370657 --- apps/codecs/libasf/asf.c | 354 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 354 insertions(+) create mode 100644 apps/codecs/libasf/asf.c (limited to 'apps/codecs/libasf/asf.c') diff --git a/apps/codecs/libasf/asf.c b/apps/codecs/libasf/asf.c new file mode 100644 index 0000000000..f65627b057 --- /dev/null +++ b/apps/codecs/libasf/asf.c @@ -0,0 +1,354 @@ +#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, struct codec_api* ci) +{ + 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; + uint32_t send_time; + uint16_t duration; + uint16_t payload_count; + int payload_length_type; + uint32_t payload_hdrlen; + int payload_datalen; + int multiple; + uint32_t replicated_length; + uint32_t media_object_number; + uint32_t media_object_offset; + 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; + + if (bufsize != length) { + /* 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, struct codec_api* ci) +{ + uint8_t tmp8, packet_flags, packet_property; + int ec_length, opaque_data, ec_length_type; + int datalen; + uint8_t data[18]; + uint8_t* datap; + 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; +} -- cgit v1.2.3