From 5778299c7ed3f82c624589bd35c82f597a8e0b64 Mon Sep 17 00:00:00 2001 From: Justin Ruggles Date: Fri, 10 Feb 2012 17:51:11 -0500 Subject: ttadec: fix last frame handling when seeking Using a frame count, as is done currently, does not work at all with seeking. Instead, when the number of samples in the final frame has been decoded, we check if only the 32-bit CRC is remaining. If so, we assume that it is the final frame. There is no longer a need to keep total_frames in TTAContext. --- libavcodec/tta.c | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-) (limited to 'libavcodec/tta.c') diff --git a/libavcodec/tta.c b/libavcodec/tta.c index 0bd7daba9c..5ed70e99c9 100644 --- a/libavcodec/tta.c +++ b/libavcodec/tta.c @@ -64,7 +64,7 @@ typedef struct TTAContext { int format, channels, bps; unsigned data_length; - int frame_length, last_frame_length, total_frames; + int frame_length, last_frame_length; int32_t *decode_buffer; @@ -198,6 +198,7 @@ static int tta_check_crc(TTAContext *s, const uint8_t *buf, int buf_size) static av_cold int tta_decode_init(AVCodecContext * avctx) { TTAContext *s = avctx->priv_data; + int total_frames; s->avctx = avctx; @@ -262,24 +263,24 @@ static av_cold int tta_decode_init(AVCodecContext * avctx) s->frame_length = 256 * avctx->sample_rate / 245; s->last_frame_length = s->data_length % s->frame_length; - s->total_frames = s->data_length / s->frame_length + - (s->last_frame_length ? 1 : 0); + total_frames = s->data_length / s->frame_length + + (s->last_frame_length ? 1 : 0); av_log(s->avctx, AV_LOG_DEBUG, "format: %d chans: %d bps: %d rate: %d block: %d\n", s->format, avctx->channels, avctx->bits_per_coded_sample, avctx->sample_rate, avctx->block_align); av_log(s->avctx, AV_LOG_DEBUG, "data_length: %d frame_length: %d last: %d total: %d\n", - s->data_length, s->frame_length, s->last_frame_length, s->total_frames); + s->data_length, s->frame_length, s->last_frame_length, total_frames); // FIXME: seek table - if (avctx->extradata_size <= 26 || s->total_frames > INT_MAX / 4 || - avctx->extradata_size - 26 < s->total_frames * 4) + if (avctx->extradata_size <= 26 || total_frames > INT_MAX / 4 || + avctx->extradata_size - 26 < total_frames * 4) av_log(avctx, AV_LOG_WARNING, "Seek table missing or too small\n"); else if (avctx->err_recognition & AV_EF_CRCCHECK) { - if (tta_check_crc(s, avctx->extradata + 22, s->total_frames * 4)) + if (tta_check_crc(s, avctx->extradata + 22, total_frames * 4)) return AVERROR_INVALIDDATA; } - skip_bits_long(&s->gb, 32 * s->total_frames); + skip_bits_long(&s->gb, 32 * total_frames); skip_bits_long(&s->gb, 32); // CRC32 of seektable if(s->frame_length >= UINT_MAX / (s->channels * sizeof(int32_t))){ @@ -325,11 +326,6 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data, init_get_bits(&s->gb, buf, buf_size*8); - // FIXME: seeking - s->total_frames--; - if (!s->total_frames && s->last_frame_length) - framelen = s->last_frame_length; - /* get output buffer */ s->frame.nb_samples = framelen; if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) { @@ -348,6 +344,7 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data, rice_init(&s->ch_ctx[i].rice, 10, 10); } + i = 0; for (p = s->decode_buffer; p < s->decode_buffer + (framelen * s->channels); p++) { int32_t *predictor = &s->ch_ctx[cur_chan].predictor; TTAFilter *filter = &s->ch_ctx[cur_chan].filter; @@ -424,9 +421,16 @@ static int tta_decode_frame(AVCodecContext *avctx, void *data, *r = *(r + 1) - *r; } cur_chan = 0; + i++; + // check for last frame + if (i == s->last_frame_length && get_bits_left(&s->gb) / 8 == 4) { + s->frame.nb_samples = framelen = s->last_frame_length; + break; + } } } + align_get_bits(&s->gb); if (get_bits_left(&s->gb) < 32) { ret = AVERROR_INVALIDDATA; goto error; -- cgit v1.2.3