Module: libav Branch: master Commit: 5778299c7ed3f82c624589bd35c82f597a8e0b64
Author: Justin Ruggles <[email protected]> Committer: Justin Ruggles <[email protected]> Date: Fri Feb 10 17:51:11 2012 -0500 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 files changed, 17 insertions(+), 13 deletions(-) diff --git a/libavcodec/tta.c b/libavcodec/tta.c index 0bd7dab..5ed70e9 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; _______________________________________________ libav-commits mailing list [email protected] https://lists.libav.org/mailman/listinfo/libav-commits
