Author: faust3 Date: Sat Aug 29 15:10:20 2009 New Revision: 5329 Log: decode subframe length in a separate function Modified: wmapro/wmaprodec.c Modified: wmapro/wmaprodec.c ============================================================================== --- wmapro/wmaprodec.c Sat Aug 29 14:53:57 2009 (r5328) +++ wmapro/wmaprodec.c Sat Aug 29 15:10:20 2009 (r5329) @@ -447,6 +447,34 @@ static av_cold int decode_init(AVCodecCo } /** + *@brief Decode the subframe length + *@param s context + *@return decoded subframe length + */ +static int decode_subframe_length(WMA3DecodeContext *s) +{ + int log2_subframe_len = 0; + int subframe_len; + /* 1 bit indicates if the subframe is of maximum length */ + if (s->max_subframe_len_bit) { + if (get_bits1(&s->gb)) + log2_subframe_len = 1 + get_bits(&s->gb, s->subframe_len_bits-1); + } else + log2_subframe_len = get_bits(&s->gb, s->subframe_len_bits); + + subframe_len = s->samples_per_frame / (1 << log2_subframe_len); + + /** sanity check the length */ + if (subframe_len < s->min_samples_per_subframe + || subframe_len > s->samples_per_frame) { + av_log(s->avctx, AV_LOG_ERROR, "broken frame: subframe_len %i\n", + subframe_len); + return 0; + } + return subframe_len; +} + +/** *@brief Decode how the data in the frame is split into subframes. * Every WMA frame contains the encoded data for a fixed number of * samples per channel. The data for every channel might be split @@ -500,7 +528,7 @@ static int decode_tilehdr(WMA3DecodeCont unsigned int channel_mask = 0; int min_channel_len; int channels_for_cur_subframe = 0; - int subframe_len; + int subframe_len = s->min_samples_per_subframe; /** minimum number of samples that need to be read */ int min_samples = s->min_samples_per_subframe; @@ -540,27 +568,9 @@ static int decode_tilehdr(WMA3DecodeCont /** if we have the choice get next subframe length from the bitstream */ if (min_samples != missing_samples) { - int log2_subframe_len = 0; - /* 1 bit indicates if the subframe is of maximum length */ - if (s->max_subframe_len_bit) { - if (get_bits1(&s->gb)) { - log2_subframe_len = 1 + - get_bits(&s->gb, s->subframe_len_bits-1); - } - } else - log2_subframe_len = get_bits(&s->gb, s->subframe_len_bits); - - subframe_len = s->samples_per_frame / (1 << log2_subframe_len); - - /** sanity check the length */ - if (subframe_len < s->min_samples_per_subframe - || subframe_len > s->samples_per_frame) { - av_log(s->avctx, AV_LOG_ERROR, - "broken frame: subframe_len %i\n", subframe_len); + if (!(subframe_len = decode_subframe_length(s))) return AVERROR_INVALIDDATA; - } - } else - subframe_len = s->min_samples_per_subframe; + } for (c = 0; c < s->num_channels; c++) { WMA3ChannelCtx* chan = &s->channel[c];