diff options
author | Jerry Jiang <jerryjiang1128@gmail.com> | 2017-02-01 23:23:04 -0800 |
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committer | Rostislav Pehlivanov <atomnuker@gmail.com> | 2017-02-08 13:59:53 +0000 |
commit | 884506dfe2e29a5b2bd2905ca4f17e277e32acb1 (patch) | |
tree | efac020fcd29af2670ddbf40faff5edb5ddf718e /libavcodec/mjpegenc.c | |
parent | 2d453188c2303da641dafb048dc1806790526dfd (diff) | |
download | ffmpeg-884506dfe2e29a5b2bd2905ca4f17e277e32acb1.tar.gz |
Implement optimal huffman encoding for (M)JPEG.
> seems to break
> make fate-vsynth1-mjpeg-444
Fixed.
Diffstat (limited to 'libavcodec/mjpegenc.c')
-rw-r--r-- | libavcodec/mjpegenc.c | 243 |
1 files changed, 178 insertions, 65 deletions
diff --git a/libavcodec/mjpegenc.c b/libavcodec/mjpegenc.c index 3d113770df..a4899c5d6e 100644 --- a/libavcodec/mjpegenc.c +++ b/libavcodec/mjpegenc.c @@ -39,39 +39,15 @@ #include "mjpeg.h" #include "mjpegenc.h" -static uint8_t uni_ac_vlc_len[64 * 64 * 2]; -static uint8_t uni_chroma_ac_vlc_len[64 * 64 * 2]; - -static av_cold void init_uni_ac_vlc(const uint8_t huff_size_ac[256], uint8_t *uni_ac_vlc_len) -{ - int i; - - for (i = 0; i < 128; i++) { - int level = i - 64; - int run; - if (!level) - continue; - for (run = 0; run < 64; run++) { - int len, code, nbits; - int alevel = FFABS(level); - - len = (run >> 4) * huff_size_ac[0xf0]; - - nbits= av_log2_16bit(alevel) + 1; - code = ((15&run) << 4) | nbits; - - len += huff_size_ac[code] + nbits; - - uni_ac_vlc_len[UNI_AC_ENC_INDEX(run, i)] = len; - // We ignore EOB as its just a constant which does not change generally - } - } -} +// Don't know, but let's guess 16 bits per code +#define MJPEG_HUFFMAN_EST_BITS_PER_CODE 16 av_cold int ff_mjpeg_encode_init(MpegEncContext *s) { MJpegContext *m; + av_assert0(s->slice_context_count == 1); + if (s->width > 65500 || s->height > 65500) { av_log(s, AV_LOG_ERROR, "JPEG does not support resolutions above 65500x65500\n"); return AVERROR(EINVAL); @@ -84,7 +60,9 @@ av_cold int ff_mjpeg_encode_init(MpegEncContext *s) s->min_qcoeff=-1023; s->max_qcoeff= 1023; - /* build all the huffman tables */ + // Build default Huffman tables. + // These may be overwritten later with more optimal Huffman tables, but + // they are needed at least right now for some processes like trellis. ff_mjpeg_build_huffman_codes(m->huff_size_dc_luminance, m->huff_code_dc_luminance, avpriv_mjpeg_bits_dc_luminance, @@ -102,12 +80,18 @@ av_cold int ff_mjpeg_encode_init(MpegEncContext *s) avpriv_mjpeg_bits_ac_chrominance, avpriv_mjpeg_val_ac_chrominance); - init_uni_ac_vlc(m->huff_size_ac_luminance, uni_ac_vlc_len); - init_uni_ac_vlc(m->huff_size_ac_chrominance, uni_chroma_ac_vlc_len); + init_uni_ac_vlc(m->huff_size_ac_luminance, m->uni_ac_vlc_len); + init_uni_ac_vlc(m->huff_size_ac_chrominance, m->uni_chroma_ac_vlc_len); s->intra_ac_vlc_length = - s->intra_ac_vlc_last_length = uni_ac_vlc_len; + s->intra_ac_vlc_last_length = m->uni_ac_vlc_len; s->intra_chroma_ac_vlc_length = - s->intra_chroma_ac_vlc_last_length = uni_chroma_ac_vlc_len; + s->intra_chroma_ac_vlc_last_length = m->uni_chroma_ac_vlc_len; + + // Buffers start out empty. + m->huff_buffer = NULL; + m->huff_ncode = 0; + m->huff_capacity = 0; + m->error = 0; s->mjpeg_ctx = m; return 0; @@ -115,71 +99,193 @@ av_cold int ff_mjpeg_encode_init(MpegEncContext *s) av_cold void ff_mjpeg_encode_close(MpegEncContext *s) { + av_freep(&s->mjpeg_ctx->huff_buffer); av_freep(&s->mjpeg_ctx); } +/** + * Encodes and outputs the entire frame in the JPEG format. + * + * @param s The MpegEncContext. + */ +void ff_mjpeg_encode_picture_frame(MpegEncContext *s) +{ + int i, nbits, code, table_id; + MJpegContext *m = s->mjpeg_ctx; + uint8_t *huff_size[4] = {m->huff_size_dc_luminance, + m->huff_size_dc_chrominance, + m->huff_size_ac_luminance, + m->huff_size_ac_chrominance}; + uint16_t *huff_code[4] = {m->huff_code_dc_luminance, + m->huff_code_dc_chrominance, + m->huff_code_ac_luminance, + m->huff_code_ac_chrominance}; + size_t total_bits = 0; + size_t bytes_needed; + + // Estimate the total size first + for (i = 0; i < m->huff_ncode; i++) { + table_id = m->huff_buffer[i].table_id; + code = m->huff_buffer[i].code; + nbits = code & 0xf; + + total_bits += huff_size[table_id][code] + nbits; + } + + bytes_needed = (total_bits + 7) / 8; + ff_mpv_reallocate_putbitbuffer(s, bytes_needed, bytes_needed); + + for (i = 0; i < m->huff_ncode; i++) { + table_id = m->huff_buffer[i].table_id; + code = m->huff_buffer[i].code; + nbits = code & 0xf; + + put_bits(&s->pb, huff_size[table_id][code], huff_code[table_id][code]); + if (nbits != 0) { + put_sbits(&s->pb, nbits, m->huff_buffer[i].mant); + } + } + + m->huff_ncode = 0; +} + +/** + * Add code and table_id to the JPEG buffer. + * + * @param s The MJpegContext which contains the JPEG buffer. + * @param table_id Which Huffman table the code belongs to. + * @param code The encoded exponent of the coefficients and the run-bits. + */ +static inline void ff_mjpeg_encode_code(MJpegContext *s, uint8_t table_id, int code) +{ + MJpegHuffmanCode *c = &s->huff_buffer[s->huff_ncode++]; + av_assert0(s->huff_ncode < s->huff_capacity); + c->table_id = table_id; + c->code = code; +} + +/** + * Add the coefficient's data to the JPEG buffer. + * + * @param s The MJpegContext which contains the JPEG buffer. + * @param table_id Which Huffman table the code belongs to. + * @param val The coefficient. + * @param run The run-bits. + */ +static void ff_mjpeg_encode_coef(MJpegContext *s, uint8_t table_id, int val, int run) +{ + int mant, code; + + if (val == 0) { + av_assert0(run == 0); + ff_mjpeg_encode_code(s, table_id, 0); + } else { + mant = val; + if (val < 0) { + val = -val; + mant--; + } + + code = (run << 4) | (av_log2_16bit(val) + 1); + + s->huff_buffer[s->huff_ncode].mant = mant; + ff_mjpeg_encode_code(s, table_id, code); + } +} + +/** + * Add the block's data into the JPEG buffer. + * + * @param s The MJpegEncContext that contains the JPEG buffer. + * @param block The block. + * @param n The block's index or number. + */ static void encode_block(MpegEncContext *s, int16_t *block, int n) { - int mant, nbits, code, i, j; - int component, dc, run, last_index, val; + int i, j, table_id; + int component, dc, last_index, val, run; MJpegContext *m = s->mjpeg_ctx; - uint8_t *huff_size_ac; - uint16_t *huff_code_ac; + + if (m->error) return; + + av_assert0(m->huff_capacity >= m->huff_ncode + 64); /* DC coef */ component = (n <= 3 ? 0 : (n&1) + 1); + table_id = (n <= 3 ? 0 : 1); dc = block[0]; /* overflow is impossible */ val = dc - s->last_dc[component]; - if (n < 4) { - ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_luminance, m->huff_code_dc_luminance); - huff_size_ac = m->huff_size_ac_luminance; - huff_code_ac = m->huff_code_ac_luminance; - } else { - ff_mjpeg_encode_dc(&s->pb, val, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance); - huff_size_ac = m->huff_size_ac_chrominance; - huff_code_ac = m->huff_code_ac_chrominance; - } + + ff_mjpeg_encode_coef(m, table_id, val, 0); + s->last_dc[component] = dc; /* AC coefs */ run = 0; last_index = s->block_last_index[n]; + table_id |= 2; + for(i=1;i<=last_index;i++) { j = s->intra_scantable.permutated[i]; val = block[j]; + if (val == 0) { run++; } else { while (run >= 16) { - put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]); + ff_mjpeg_encode_code(m, table_id, 0xf0); run -= 16; } - mant = val; - if (val < 0) { - val = -val; - mant--; - } - - nbits= av_log2_16bit(val) + 1; - code = (run << 4) | nbits; - - put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]); - - put_sbits(&s->pb, nbits, mant); + ff_mjpeg_encode_coef(m, table_id, val, run); run = 0; } } /* output EOB only if not already 64 values */ if (last_index < 63 || run != 0) - put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]); + ff_mjpeg_encode_code(m, table_id, 0); } -void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]) +// Possibly reallocate the huffman code buffer, assuming blocks_per_mb. +// Set s->mjpeg_ctx->error on ENOMEM. +static void realloc_huffman(MpegEncContext *s, int blocks_per_mb) { - int i; + MJpegContext *m = s->mjpeg_ctx; + size_t num_mbs, num_blocks, num_codes; + MJpegHuffmanCode *new_buf; + if (m->error) return; + // Make sure we have enough space to hold this frame. + num_mbs = s->mb_width * s->mb_height; + num_blocks = num_mbs * blocks_per_mb; + av_assert0(m->huff_ncode <= + (s->mb_y * s->mb_width + s->mb_x) * blocks_per_mb * 64); + num_codes = num_blocks * 64; + + new_buf = av_fast_realloc(m->huff_buffer, &m->huff_capacity, + num_codes * sizeof(MJpegHuffmanCode)); + if (!new_buf) { + m->error = AVERROR(ENOMEM); + } else { + m->huff_buffer = new_buf; + } +} + +int ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]) +{ + int i, is_chroma_420; + + // Number of bits used depends on future data. + // So, nothing that relies on encoding many times and taking the + // one with the fewest bits will work properly here. + if (s->i_tex_bits != MJPEG_HUFFMAN_EST_BITS_PER_CODE * + s->mjpeg_ctx->huff_ncode) { + av_log(NULL, AV_LOG_ERROR, "Unsupported encoding method\n"); + return AVERROR(EINVAL); + } + if (s->chroma_format == CHROMA_444) { + realloc_huffman(s, 12); encode_block(s, block[0], 0); encode_block(s, block[2], 2); encode_block(s, block[4], 4); @@ -196,10 +302,12 @@ void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]) encode_block(s, block[11], 11); } } else { + is_chroma_420 = (s->chroma_format == CHROMA_420); + realloc_huffman(s, 5 + (is_chroma_420 ? 1 : 3)); for(i=0;i<5;i++) { encode_block(s, block[i], i); } - if (s->chroma_format == CHROMA_420) { + if (is_chroma_420) { encode_block(s, block[5], 5); } else { encode_block(s, block[6], 6); @@ -207,8 +315,11 @@ void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64]) encode_block(s, block[7], 7); } } + if (s->mjpeg_ctx->error) + return s->mjpeg_ctx->error; - s->i_tex_bits += get_bits_diff(s); + s->i_tex_bits = MJPEG_HUFFMAN_EST_BITS_PER_CODE * s->mjpeg_ctx->huff_ncode; + return 0; } // maximum over s->mjpeg_vsample[i] @@ -261,7 +372,9 @@ FF_MPV_COMMON_OPTS { "left", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 1 }, INT_MIN, INT_MAX, VE, "pred" }, { "plane", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 2 }, INT_MIN, INT_MAX, VE, "pred" }, { "median", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = 3 }, INT_MIN, INT_MAX, VE, "pred" }, - +{ "huffman", "Huffman table strategy", OFFSET(huffman), AV_OPT_TYPE_INT, { .i64 = HUFFMAN_TABLE_DEFAULT }, 0, NB_HUFFMAN_TABLE_OPTION - 1, VE, "huffman" }, + { "default", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = HUFFMAN_TABLE_DEFAULT }, INT_MIN, INT_MAX, VE, "huffman" }, + { "optimal", NULL, 0, AV_OPT_TYPE_CONST, { .i64 = HUFFMAN_TABLE_OPTIMAL }, INT_MIN, INT_MAX, VE, "huffman" }, { NULL}, }; 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