Author: thilo.borgmann Date: Thu Jun 18 16:04:42 2009 New Revision: 4489 Log: Adds structure and functionality to read and process ALSSpecifigConfig during the initialization. Modified: als/alsdec.c Modified: als/alsdec.c ============================================================================== --- als/alsdec.c Thu Jun 18 07:05:42 2009 (r4488) +++ als/alsdec.c Thu Jun 18 16:04:42 2009 (r4489) @@ -26,13 +26,239 @@ */ +//#define DEBUG + + #include "avcodec.h" +#include "get_bits.h" + + +typedef struct { + uint32_t als_id; ///< ALS identifier + uint32_t samp_freq; ///< Sampling frequency in Hz + uint32_t samples; ///< Number of samples (per channel). = 0xFFFFFFFF if unknown. + int channels; ///< Number of channels + int file_type; ///< Not used. Provided for debugging. + int resolution; ///< 000 = 8-bit; 001 = 16-bit; 010 = 24-bit; 011 = 32-bit + int floating; ///< 1 = IEEE 32-bit floating-point, 0 = integer + int msb_first; ///< Original byte order of the input audio data + int frame_length; ///< Frame Length + int random_access; ///< Distance between RA frames (in frames, 0...255) + int ra_flag; ///< Indicates where the size of ra units is stored. + int adapt_order; ///< Adaptive order: 1 = on, 0 = off + int coef_table; ///< Table index of rice code parameters + int long_term_prediction; ///< Long term prediction (LTP): 1 = on, 0 = off + int max_order; ///< Maximum prediction order (0..1023) + int block_switching; ///< Number of block switching levels + int bgmc_mode; ///< BGMC Mode: 1 = on, 0 = off (Rice coding only) + int sb_part; ///< Sub-block partition + int joint_stereo; ///< Joint Stereo: 1 = on, 0 = off + int mc_coding; ///< Extended inter-channel coding: 1 = on, 0 = off + int chan_config; ///< Indicates that a chan_config_info field is present + int chan_sort; ///< Channel rearrangement: 1 = on, 0 = off + int crc_enabled; ///< Indicates that the crc field is present + int RLSLMS; ///< Use RLS-LMS predictor: 1 = on, 0 = off + int aux_data_enabled; ///< Indicates that auxiliary data is present + int chan_config_info; ///< Mapping of channels to loudspeaker locations + int *chan_pos; ///< Original channel positions + uint32_t header_size; ///< Header size of original audio file in bytes. Provided for debugging. + uint32_t trailer_size; ///< Trailer size of original audio file in bytes. Provided for debugging. + uint32_t crc; ///< 32-bit CCITT-32 CRC checksum +} ALSSpecificConfig; typedef struct { + AVCodecContext *avctx; + ALSSpecificConfig sconf; + unsigned int num_frames; ///< Number of frames to decode. 0 if unknown. + unsigned int last_frame_length; ///< Length of the last frame to decode. 0 if unknown. } ALSDecContext; +#ifdef DEBUG +static av_cold void dprint_specific_config(ALSDecContext *ctx) +{ + AVCodecContext *avctx = ctx->avctx; + ALSSpecificConfig *sconf = &ctx->sconf; + + dprintf(avctx, "als_id = %x\n", sconf->als_id); + dprintf(avctx, "samp_freq = %i\n", sconf->samp_freq); + dprintf(avctx, "samples = %i\n", sconf->samples); + dprintf(avctx, "channels = %i\n", sconf->channels); + dprintf(avctx, "file_type = %i\n", sconf->file_type); + dprintf(avctx, "resolution = %i\n", sconf->resolution); + dprintf(avctx, "floating = %i\n", sconf->floating); + dprintf(avctx, "msb_first = %i\n", sconf->msb_first); + dprintf(avctx, "frame_length = %i\n", sconf->frame_length); + dprintf(avctx, "ra_flag = %i\n", sconf->ra_flag); + dprintf(avctx, "adapt_order = %i\n", sconf->adapt_order); + dprintf(avctx, "coef_table = %i\n", sconf->coef_table); + dprintf(avctx, "long_term_prediction = %i\n", sconf->long_term_prediction); + dprintf(avctx, "max_order = %i\n", sconf->max_order); + dprintf(avctx, "block_switching = %i\n", sconf->block_switching); + dprintf(avctx, "bgmc_mode = %i\n", sconf->bgmc_mode); + dprintf(avctx, "sb_part = %i\n", sconf->sb_part); + dprintf(avctx, "joint_stereo = %i\n", sconf->joint_stereo); + dprintf(avctx, "mc_coding = %i\n", sconf->mc_coding); + dprintf(avctx, "chan_config = %i\n", sconf->chan_config); + dprintf(avctx, "chan_sort = %i\n", sconf->chan_sort); + dprintf(avctx, "crc_enabled = %i\n", sconf->crc_enabled); + dprintf(avctx, "RLSLMS = %i\n", sconf->RLSLMS); + dprintf(avctx, "aux_data_enabled = %i\n", sconf->aux_data_enabled); + dprintf(avctx, "chan_config_info = %i\n", sconf->chan_config_info); + dprintf(avctx, "header_size = %i\n", sconf->header_size); + dprintf(avctx, "trailer_size = %i\n", sconf->trailer_size); + dprintf(avctx, "crc_enabled = %i\n", sconf->crc_enabled); + + dprintf(avctx, " num_frames = %i\n", ctx->num_frames); + dprintf(avctx, " last_frame_length = %i\n", ctx->last_frame_length); +} +#endif + + +/** Reads an ALSSpecificConfig from a buffer into the output struct. + */ +static av_cold int read_specific_config(ALSDecContext *ctx, + const uint8_t *buffer, int buffer_size, + ALSSpecificConfig *sconf) +{ + GetBitContext gb; + uint64_t ht_size; + int i; + + if (buffer_size < 22) + return -1; + + init_get_bits(&gb, buffer, buffer_size * 8); + + // read the fixed items + sconf->als_id = get_bits_long(&gb, 32); + sconf->samp_freq = get_bits_long(&gb, 32); + sconf->samples = get_bits_long(&gb, 32); + sconf->channels = get_bits(&gb, 16) + 1; + sconf->file_type = get_bits(&gb, 3); + sconf->resolution = get_bits(&gb, 3); + sconf->floating = get_bits1(&gb); + sconf->msb_first = get_bits1(&gb); + sconf->frame_length = get_bits(&gb, 16) + 1; + sconf->random_access = get_bits(&gb, 8); + sconf->ra_flag = get_bits(&gb, 2); + sconf->adapt_order = get_bits1(&gb); + sconf->coef_table = get_bits(&gb, 2); + sconf->long_term_prediction = get_bits1(&gb); + sconf->max_order = get_bits(&gb, 10); + sconf->block_switching = get_bits(&gb, 2); + sconf->bgmc_mode = get_bits1(&gb); + sconf->sb_part = get_bits1(&gb); + sconf->joint_stereo = get_bits1(&gb); + sconf->mc_coding = get_bits1(&gb); + sconf->chan_config = get_bits1(&gb); + sconf->chan_sort = get_bits1(&gb); + sconf->crc_enabled = get_bits1(&gb); + sconf->RLSLMS = get_bits1(&gb); + skip_bits(&gb, 5); // skip 5 reserved bits + sconf->aux_data_enabled = get_bits1(&gb); + buffer_size -= 22; + + + // check for ALSSpecificConfig struct + if (sconf->als_id != MKBETAG('A','L','S','\0')) + return -1; + + + // calculate total number of frames to decode if possible + if (sconf->samples != 0xFFFFFFFF) { + ctx->num_frames = ((sconf->samples - 1) / sconf->frame_length) + 1; + ctx->last_frame_length = sconf->samples % ctx->sconf.frame_length; + if (!ctx->last_frame_length) { + ctx->last_frame_length = sconf->frame_length; + } + } else { + ctx->num_frames = 0; + ctx->last_frame_length = 0; + } + + + // read channel config + if (sconf->chan_config) { + if (buffer_size < 2) + return -1; + + sconf->chan_config_info = get_bits(&gb, 16); + buffer_size -= 2; + // TODO: use this to set avctx->channel_layout + } + + + // read channel sorting + if (sconf->chan_sort && sconf->channels > 1) { + int chan_pos_bits = av_log2((sconf->channels - 1) << 1); + int bytes_needed = (sconf->channels * chan_pos_bits + 7) / 8; + if (buffer_size < bytes_needed) + return -1; + + if(!(sconf->chan_pos = av_malloc(sconf->channels * sizeof(int)))) + return -1; + + for (i = 0; i < sconf->channels; i++) { + sconf->chan_pos[i] = get_bits(&gb, chan_pos_bits); + } + + align_get_bits(&gb); + buffer_size -= bytes_needed; + } else { + sconf->chan_sort = 0; + } + + + // read fixed header and trailer sizes, if size = 0xFFFFFFFF then there is no data field! + if (buffer_size < 8) + return -1; + + sconf->header_size = get_bits_long(&gb, 32); + sconf->trailer_size = get_bits_long(&gb, 32); + if (sconf->header_size == 0xFFFFFFFF) + sconf->header_size = 0; + if (sconf->trailer_size == 0xFFFFFFFF) + sconf->trailer_size = 0; + + ht_size = sconf->header_size + sconf->trailer_size; + + buffer_size -= 8; + + + // skip the header and trailer data + if (buffer_size < ht_size) + return -1; + + ht_size *= 8; + + while (ht_size > 0) { + int len = FFMIN(ht_size, INT32_MAX); + skip_bits_long(&gb, len); + ht_size -= len; + } + + buffer_size -= ht_size; + + + // read the crc data + if (sconf->crc_enabled) { + if (buffer_size < 4) + return -1; + + sconf->crc = get_bits_long(&gb, 32); + } + + + // no need to read the rest of ALSSpecificConfig (ra_unit_size & aux data) +#ifdef DEBUG + dprint_specific_config(ctx); +#endif + return 0; +} + + /** Decodes an ALS frame. */ static int decode_frame(AVCodecContext *avctx, @@ -47,6 +273,31 @@ static int decode_frame(AVCodecContext * */ static av_cold int decode_init(AVCodecContext *avctx) { + ALSDecContext *ctx = avctx->priv_data; + ctx->avctx = avctx; + + if (!avctx->extradata) { + av_log(avctx, AV_LOG_ERROR, "Missing required ALS extradata.\n"); + return -1; + } + + if (read_specific_config(ctx, avctx->extradata + 6, + avctx->extradata_size - 6, &ctx->sconf)) { + av_log(avctx, AV_LOG_ERROR, "Reading ALSSpecificConfig failed.\n"); + return -1; + } + + avctx->sample_rate = ctx->sconf.samp_freq; + avctx->channels = ctx->sconf.channels; + + if (ctx->sconf.floating) { + avctx->sample_fmt = SAMPLE_FMT_FLT; + avctx->bits_per_raw_sample = 32; + } else { + avctx->sample_fmt = ctx->sconf.resolution > 1 ? SAMPLE_FMT_S32 : SAMPLE_FMT_S16; + avctx->bits_per_raw_sample = (ctx->sconf.resolution + 1) * 8; + } + return 0; } @@ -55,6 +306,10 @@ static av_cold int decode_init(AVCodecCo */ static av_cold int decode_end(AVCodecContext *avctx) { + ALSDecContext *ctx = avctx->priv_data; + + av_freep(&ctx->sconf.chan_pos); + return 0; }