From 98c97994c5b90bdae02accb155eeceeb5224b8ef Mon Sep 17 00:00:00 2001 From: Anton Khirnov Date: Tue, 29 Mar 2016 04:09:14 +0200 Subject: h264: decouple extradata parsing from the decoder This will allow decoupling the parser from the decoder. --- libavcodec/h264.c | 133 ++---------------------------------------------------- 1 file changed, 5 insertions(+), 128 deletions(-) (limited to 'libavcodec/h264.c') diff --git a/libavcodec/h264.c b/libavcodec/h264.c index 060feb9478..7db97ef157 100644 --- a/libavcodec/h264.c +++ b/libavcodec/h264.c @@ -278,117 +278,6 @@ fail: return AVERROR(ENOMEM); // ff_h264_free_tables will clean up for us } -static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size, - int parse_extradata); - -/* There are (invalid) samples in the wild with mp4-style extradata, where the - * parameter sets are stored unescaped (i.e. as RBSP). - * This function catches the parameter set decoding failure and tries again - * after escaping it */ -static int decode_extradata_ps_mp4(H264Context *h, const uint8_t *buf, int buf_size) -{ - int ret; - - ret = decode_nal_units(h, buf, buf_size, 1); - if (ret < 0 && !(h->avctx->err_recognition & AV_EF_EXPLODE)) { - GetByteContext gbc; - PutByteContext pbc; - uint8_t *escaped_buf; - int escaped_buf_size; - - av_log(h->avctx, AV_LOG_WARNING, - "SPS decoding failure, trying again after escaping the NAL\n"); - - if (buf_size / 2 >= (INT16_MAX - AV_INPUT_BUFFER_PADDING_SIZE) / 3) - return AVERROR(ERANGE); - escaped_buf_size = buf_size * 3 / 2 + AV_INPUT_BUFFER_PADDING_SIZE; - escaped_buf = av_mallocz(escaped_buf_size); - if (!escaped_buf) - return AVERROR(ENOMEM); - - bytestream2_init(&gbc, buf, buf_size); - bytestream2_init_writer(&pbc, escaped_buf, escaped_buf_size); - - while (bytestream2_get_bytes_left(&gbc)) { - if (bytestream2_get_bytes_left(&gbc) >= 3 && - bytestream2_peek_be24(&gbc) <= 3) { - bytestream2_put_be24(&pbc, 3); - bytestream2_skip(&gbc, 2); - } else - bytestream2_put_byte(&pbc, bytestream2_get_byte(&gbc)); - } - - escaped_buf_size = bytestream2_tell_p(&pbc); - AV_WB16(escaped_buf, escaped_buf_size - 2); - - ret = decode_nal_units(h, escaped_buf, escaped_buf_size, 1); - av_freep(&escaped_buf); - if (ret < 0) - return ret; - } - - return 0; -} - -int ff_h264_decode_extradata(H264Context *h) -{ - AVCodecContext *avctx = h->avctx; - int ret; - - if (avctx->extradata[0] == 1) { - int i, cnt, nalsize; - unsigned char *p = avctx->extradata; - - h->is_avc = 1; - - if (avctx->extradata_size < 7) { - av_log(avctx, AV_LOG_ERROR, - "avcC %d too short\n", avctx->extradata_size); - return AVERROR_INVALIDDATA; - } - /* sps and pps in the avcC always have length coded with 2 bytes, - * so put a fake nal_length_size = 2 while parsing them */ - h->nal_length_size = 2; - // Decode sps from avcC - cnt = *(p + 5) & 0x1f; // Number of sps - p += 6; - for (i = 0; i < cnt; i++) { - nalsize = AV_RB16(p) + 2; - if (p - avctx->extradata + nalsize > avctx->extradata_size) - return AVERROR_INVALIDDATA; - ret = decode_extradata_ps_mp4(h, p, nalsize); - if (ret < 0) { - av_log(avctx, AV_LOG_ERROR, - "Decoding sps %d from avcC failed\n", i); - return ret; - } - p += nalsize; - } - // Decode pps from avcC - cnt = *(p++); // Number of pps - for (i = 0; i < cnt; i++) { - nalsize = AV_RB16(p) + 2; - if (p - avctx->extradata + nalsize > avctx->extradata_size) - return AVERROR_INVALIDDATA; - ret = decode_extradata_ps_mp4(h, p, nalsize); - if (ret < 0) { - av_log(avctx, AV_LOG_ERROR, - "Decoding pps %d from avcC failed\n", i); - return ret; - } - p += nalsize; - } - // Store right nal length size that will be used to parse all other nals - h->nal_length_size = (avctx->extradata[4] & 0x03) + 1; - } else { - h->is_avc = 0; - ret = decode_nal_units(h, avctx->extradata, avctx->extradata_size, 1); - if (ret < 0) - return ret; - } - return 0; -} - static int h264_init_context(AVCodecContext *avctx, H264Context *h) { int i; @@ -462,7 +351,9 @@ av_cold int ff_h264_decode_init(AVCodecContext *avctx) } if (avctx->extradata_size > 0 && avctx->extradata) { - ret = ff_h264_decode_extradata(h); + ret = ff_h264_decode_extradata(avctx->extradata, avctx->extradata_size, + &h->ps, &h->is_avc, &h->nal_length_size, + avctx->err_recognition, avctx); if (ret < 0) { ff_h264_free_context(h); return ret; @@ -919,8 +810,7 @@ static int get_last_needed_nal(H264Context *h) return nals_needed; } -static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size, - int parse_extradata) +static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size) { AVCodecContext *const avctx = h->avctx; unsigned context_count = 0; @@ -956,19 +846,6 @@ static int decode_nal_units(H264Context *h, const uint8_t *buf, int buf_size, continue; again: - /* Ignore every NAL unit type except PPS and SPS during extradata - * parsing. Decoding slices is not possible in codec init - * with frame-mt */ - if (parse_extradata && HAVE_THREADS && - (h->avctx->active_thread_type & FF_THREAD_FRAME) && - (nal->type != NAL_PPS && nal->type != NAL_SPS)) { - if (nal->type < NAL_AUD || nal->type > NAL_AUXILIARY_SLICE) - av_log(avctx, AV_LOG_INFO, - "Ignoring NAL unit %d during extradata parsing\n", - nal->type); - nal->type = NAL_FF_IGNORE; - } - // FIXME these should stop being context-global variables h->nal_ref_idc = nal->ref_idc; h->nal_unit_type = nal->type; @@ -1183,7 +1060,7 @@ out: return buf_index; } - buf_index = decode_nal_units(h, buf, buf_size, 0); + buf_index = decode_nal_units(h, buf, buf_size); if (buf_index < 0) return AVERROR_INVALIDDATA; -- cgit v1.2.1